Electrical household appliance drive device

Abstract

The invention relates to an electrical household appliance drive device for the force-loaded and speed-dependent adjustment of moving parts, 1. such as a door opener for opening a door of a dishwasher, within the household appliance, comprising an electromotive actuator with at least one motor shaft which is rotatable at a constant speed, and a preferably axially displaceable drive rotary shaft which runs parallel to the motor shaft, for directly or indirectly driving the moving part, wherein at least one conical component arranged on the drive rotary shaft, which is connected to the motor shaft in a rotationally locked manner by means of at least one drive belt and changes the value of a force to be transmitted and a rotational speed to be transmitted.

Description

The invention relates to a domestic electric appliance drive device for the power-operated and speed-dependent adjustment of movable parts according to the preamble of claim 1.Door openers for domestic appliances are known in a wide variety of designs. For example, a door opener for pressing open the door of a dishwasher can be designed in such a way that it has a door opener rod which can be driven by an electric motor via a toothed drive and which is designed at a leading end for engagement with a laterally arranged door lock. By advancing and retracting the door opening rod, the closed door can be pushed open a gap far and, provided the door opening rod is in engagement with the door lock, the gap-opened door can be pulled closed again.It is also frequently desired that the hinged door of a dishwasher or a washing machine opens at least partially automatically after completion of a washing process, in order to enable a final drying process, for example in the case of a dishwasher after a wash cycle, by the door being opened a bit in order to allow hot steam to escape from the washing space. If, in the case of such independent opening of the door, the course of the opening is interrupted by a counteracting resistance force, as can be the case, for example, if a person is located in front of the door, this opening process is intended to be interrupted by itself in a simple and reliable manner, in particular without the aid of sensors.It is also conceivable that such doors of dishwashers are only based on a desired closing process and then automatically completely close the closing process by automaticity, in that a mechanism pulls the door onto the rest of the housing. In this case, it is conceivable that such a closing process should be automatically interrupted, provided, for example, hand parts are still arranged between the door and the remaining housing of the dishwasher.In all the aforementioned cases, it is particularly often desirable that during an opening operation or also during a closing operation of such doors, different speeds and force values are used for opening and / or closing the door in order to be able to achieve different states in the course of such an opening or closing operation. For example, a different application of force should act on the door when the door is placed in the final closing state with increased force at the end of a closing operation, namely against the resistance forces of seals, rubber parts etc.However, these increased force values in this portion of a closing operation are not desired in a preceding time phase of the closing operation, in which the door is to be closed at lower force values and lower speed, in order thereby to avoid the risk of injuries.Although there are already speed- and force-value-dependent door openers or drive devices for doors of dishwashers and washing machines, these are generally designed with gears in order to achieve a corresponding change in the speeds. This has the consequence that, owing to the construction of these gears, a loud drive is obtained.JP 2008-280 670 A discloses a drive unit of an opening and closing body for vehicles.DE 198 29 209 A1 relates to an actuating drive, in particular a window lifter or window lifter. Sunroof drive for a motor vehicle using a cable drive drum.Accordingly, it is an object of the invention to provide a drive device for domestic electric appliances for the force-loaded and speed-dependent adjustment of movable parts, which is quiet in its mode of operation and has a simple structure and thus enables cost-effective production.This object is achieved according to the features of claim 1.According to the invention, the drive device for domestic electrical appliances for the force-loaded and speed-dependent adjustment of movable parts, such as a door opener for opening a door of a dishwasher, within the domestic appliance is characterised in that it has, on the one hand, an electromotive actuator with at least one motor shaft which is rotatable at constant speed, has a preferably axially displaceable drive rotary shaft which runs parallel to the motor shaft, for the direct or indirect drive of the movable part, and, on the other hand, comprises at least one conical component which is arranged on / on the drive rotary shaft and is connected to the motor shaft in a rotationally locked manner by means of at least one drive belt and changes the value of a force to be transmitted and of a speed to be transmitted.By using a conical component according to the invention, the drive belt can rotate at different positions of this conical shape during a rotation process and thus transmit different rotational speeds to the drive rotation shaft from the motor shaft side. This has the consequence that different speeds can be transmitted to, for example, a door opener which is connected at least indirectly to the drive rotation shaft.Since both the motor shaft and the drive rotation shaft rotate and are preferably aligned parallel to one another, a desired rotational speed of the drive rotation shaft can be established by means of the force- and speed-transmitting drive belt on account of the conical shape of the conical component as a function of the instantaneous position of the drive belt. This is possible, for example, during an opening operation in which rapid opening of a door of a dishwasher is initially desired and consequently the drive belt is arranged in a region of the conical component which has a smaller diameter. In the subsequent second part of an opening operation, a slower opening of the door may be desired, so that at this time period, i.e. the second time period of the opening operation, the drive belt is arranged at a position of the conical component which has a larger diameter of the conical component. Thus, at this point, a lower speed is transmitted from the drive rotation shaft to a door opener mechanism connected thereto.The conical component, which can of course also represent a truncated cone or any other section of a cone and which is formed rotationally symmetrically, is arranged stationary on the drive rotation shaft so that it can rotate the drive rotation shaft as it is itself driven by the drive belt.The conical component has annular depressions arranged one behind the other, running all around the circumference, for inserting the drive belt according to a preferred embodiment. This allows the drive belt to be positioned within the recess or recesses in a targeted manner and not to leave its position on the conical component during an opening operation or a closing operation and to drift in the direction of a position with a lower diameter of the conical component.The depressions, which have different diameters and which are arranged one behind the other or next to one another, can also be connected to one another as annular depressions in such a way that they form, in their entirety or in parts thereof, a spiral which circulates the conical component or a plurality of spirals. This has the consequence that the drive belt runs over a spiral path on the conical component during the opening or closing process and that a speed change of the drive rotary shaft can also be achieved by this spiral-shaped run.Depending on how the spiral runs, i.e. whether it runs around to the left or right and which pitch it has, the opening and closing process can be provided with different speeds and different force values in different time segments. The different force values are produced in that the drive belt, in a position of the conical component in which a larger diameter is present, also assumes a larger contact surface and thus a larger friction surface on the conical component. Thus, a greater force transmission can also take place. When positioning the drive belt in the region of the conical component, in which a smaller diameter of the component is present, a smaller bearing surface of the drive belt on the conical component is possible and thus also a smaller force transmission is possible.As soon as a limit value of a force transmission is reached, i.e. a slipping of the drive belt on the conical component would take place because of high resistance forces, no force transmission any longer takes place to the drive rotation shaft and thus also an opening or closing process of its end. This can be advantageous, for example, if finger parts of a user are still between the door and the remaining device parts during a closing operation and these are not violated by such a break due to increased resistance force. For this purpose, it is necessary for the resistance forces between the drive belt and the conical component or its surface to be adjusted by appropriate formation of the surface in such a way that limit values for injury to persons or body parts or finger parts are also thereby observed. It is thus not necessary to install a separate slip clutch for such cases, since the belt drive can itself represent a slip clutch.According to a preferred embodiment, the drive belt can pass through different depressions with different diameters during a single adjusting operation for adjusting the movable part, in that the drive belt changes its position with respect to the conical component. This can be done, for example, by displacing the drive rotation shaft in its longitudinal direction during an adjustment process for adjusting the movable part. This means that, although the shaft is fastened per se by means of bearings to a housing of the drive device, it can be displaced within these bearings in order to keep the drive belt positioned in the same way with respect to the motor shaft, it is possible to keep the drive rotation shaft positioned in a displaced manner with respect to the drive belt. This makes it possible in a simple manner to prevent the rotational speeds and the transmission of force without the drive belt having to be deflected undesirably strongly in the lateral direction for this purpose if a different positioning of the drive frame on the conical component and thus a different diameter of the conical component is desired.Preferably, the drive rotation shaft may additionally include at least one worm wheel for driving at least one gear, which meshes with a toothed rail of a presser to convert a rotational movement into a linear movement of the presser. This makes it possible for a presser to be driven with the drive rotary shaft, both during a closing operation and during an opening operation. If the drive rotary shaft can assume different speeds, as described, the presser can thus also be opened or displaced or closed or retracted at different speeds in different time intervals.Further advantageous embodiments are given in conjunction with the following drawing. The following are shown here: FIG. 1 shows a perspective detail illustration of a front and top view of a dishwasher in the closed state with a built-in door opener according to the invention; FIG. 2 shows a perspective detail illustration of the dishwasher shown in FIG. 1, but with a slightly open door; FIG. 3 is a plan view of the door opener according to an embodiment of the invention; FIG. 4 shows a detail plan view of the door opener according to a further embodiment with a worm wheel in a first position; FIG. 5 shows the detail plan view illustrated in FIG. 4 with a worm wheel in a second position; FIG. 6 is a fragmentary plan view of the door opener according to the invention according to a further embodiment of the invention; and FIG. 7 is a top view of the embodiment according to FIG. 6, but with a worm wheel in a new positioning.FIG. 1 shows a perspective front and top view of a detail of a dishwasher 1, which is illustrated with a closed door 2. In the upper region 2 aof the closed door 2 there is a non-visible door lock with individual components which are not shown in detail here and which interact with a door opener 5 during an opening operation.A door handle 3 is provided in the door for opening the same. A door opener 5 according to the invention is arranged in the upper region of the dishwasher, i.e. in the upper wall element 4.FIG. 2 shows the perspective illustration of the dishwasher 1 shown in FIG. 1 with the door open. It can be seen from this illustration that the door opener 5 has extended a presser 6 which can be moved according to the double arrow 7 in order to easily open the door following a flushing process for discharging vapors. For this purpose, the presser 6 pushes the door forward in the upper region 2a.FIG. 3 shows a top view of the door opener 5 according to the invention. It can be clearly seen from this illustration that the presser 6 can be moved forwards or backwards according to a linear movement 7 in order to press a door, not illustrated in any more detail here, as shown in FIG. 2. For this purpose, the presser 6 has a toothed rail 6a which can be driven by means of a toothed wheel 20.An actuator 10, which can be designed as an electric motor, is arranged in a housing 8 of the door opener 5. This actuator 10 drives an output shaft 11 that rotates at a constant speed due to the drive by the actuator 10.The output shaft 11 is in turn connected via a belt drive 12 to a longitudinal rotation shaft 14 which is rotatably mounted in the bearings 15 and 16 with respect to the housing 8.The belt engages a groove-like recess of a plurality of recesses within a conical member 13 which is fixedly mounted thereon with respect to the longitudinal rotation shaft 14.A helical compression spring 17 ensures that a distance is maintained between the conical component 13 and a component 16 which is stationary with respect to the housing 8, in order thereby to keep a worm wheel 18 still in engagement with the gearwheel 19 in the region of the circumferential edge 19 a. The longitudinal rotation shaft 14 is slidable in the longitudinal direction 23, as shown in FIG. 4.The two gearwheels 19 and 20 are rotatably mounted according to the double arrows 21, 22 and can move in mutually intermeshing fashion in such a way that a rotation of the worm wheel 18 moves the toothed rail 6 avia the two gearwheels forward and rearward, whereupon the presser 6 can press a door by undergoing a linear movement according to the double arrow 7.According to one embodiment of the invention, FIGS. 4 and 5 show a detail of the door opener according to the invention in plan view, wherein the two figures differ in that both the belt 12 and the worm wheel 18 are arranged at two different positions.As already mentioned, the longitudinal rotation shaft 14 is arranged displaceably in the direction of the double arrow 23, i.e. along its axis. This has the consequence that this shaft 14 can be displaced even if the belt 12 continues to drive the conical component 27 at the constant speed of the output shaft and at the same time, however, the toothed rail 6 aof the presser 6 cannot be moved any further, since an external resistance force, not shown in detail here, acts on the presser 6. The different positionings of the drive belt on the conical component 27, i.e. in different depressions, result in the transmission of different rotational speeds and force transmissions due to different diameters.Since the conical member 27 as well as the worm wheel 18 are firmly connected to the longitudinal rotation shaft 14, both members are displaced together with the longitudinal rotation shaft to the right until the worm wheel 18 is rotated out of engagement with the gear 19 and its teeth and thereby a force decoupling takes place between the worm wheel 18 and the gear 19. Then no further force transmission of the worm wheel 18 to the gearwheel 19 and the toothed rail 6 atakes place, as a result of which the presser 6 no longer wishes to move further forwards.The gears 19, 20 are arranged rotatably with the two axles 25 and 26, as is shown by the arrows 21, 22, which are here shown in the direction of rotation of the gears.If the actuator 10 is now switched on, the output shaft 11 is driven. A pulley 11 disposed on the output shaft is also driven and moves a closed belt 12 to thereby drive the cone-shaped member 27 as well. For this purpose, the conical component has different depressions 27 which are oriented parallel to one another and have different diameters in their course, in order to enable different door opening speeds by appropriate arrangement of the belt 12. This is because the speed of rotation of the longitudinal rotary shaft 14 finally determines, via the worm wheel 18 and the gears 19, 20, the speed of the linear movement 7 of the toothed rail 6a of the presser and thus of the entire pressing-on operation.Comparing the two FIGS. 4 and 5, it is clear that by selecting a different recess 27 of the conical component 24 for the engaging belt 12, a different speed for the rotational movement of the longitudinal rotation shaft 14 is achieved, even though the actuator 10 has a constant speed.FIGS. 6 and 7 show a detail illustration and a plan view of a further embodiment of the door opener according to the invention. In this illustration, although the conical component 13 is likewise equipped with individual depressions 28, these depressions are connected to one another in such a way that they overall form a spiral in their course. Thus, the speed and also the force value of the moving presser and the rotating longitudinal rotation shaft 14 can be reduced by initially engaging the belt to the right with the conical member 13 and then unwinding it to the left on the conical member 13 due to the spiral course of the depressions 28. This results in the deceleration of the rotational movement of the longitudinal rotation shaft 14 because the diameter of the tapered member 13 increases from right to left.Upon closer observation of the illustration shown in FIG. 7, it can be established that the helical spring 17 is acted upon by force or pressure, that is to say that the longitudinal rotation shaft 14 is displaced to the right according to the displacement movement 23. This takes place in the situation in which the presser 6 experiences a resistance force counter to its direction of movement during the pressing-on operation, whereupon the worm wheel 18 is still driven by the actuator 10 and the belt 12, but is hereby displaced to the right on account of the possible displacement movement of the longitudinal rotation shaft 14 and comes out of the engagement of the gearwheel 19. This has the consequence that in the position of the worm wheel 18 illustrated in FIG. 7, a complete force decoupling has taken place between the worm wheel 18 or the longitudinal rotation shaft 14 on the one hand and the gearwheels 19, 20 and the presser 6 on the other hand. Thus, the presser 6 is no longer acted upon by a force and does not attempt to press the door of the dishwasher against a resistance force not shown in detail here.List of reference characters1 Dishwasher 2 door 2 a Oberseite of the door 3 door handle 4 Upper wall elements of the dishwasher 5 door opener 6 presser 6 a Zahn rail 7 presser movement direction 8 door opener housing 10 actuator 11 output shaft 11 aRoll 12 Belt 13 conical component 14 longitudinal rotation shaft 15 Bearing 16 Bearing / stationary component 17 Spiral spring 18 Worm wheel 19 Gearwheel 20 Gearwheel 21 Circumferential direction 22 Circumferential direction 19 a Circumferential side, circumferential edge 23 Longitudinal displacements 24 conical component 25 Axis 26 Axis 27 Depressions 28 Depressions

Claims

Domestic electrical appliance drive device for the force-loaded and speed-dependent adjustment of movable parts within the domestic appliance (1), comprising: - an electric motor actuator (10) with at least one motor shaft (11), which is rotatable at constant speed, and - a preferably axially displaceable drive rotation shaft (14), which runs parallel to the motor shaft (11), for the direct or indirect drive of the movable part (5), characterised byat least one conical component (13, 24), which is arranged on the drive rotation shaft (14) and is connected in a rotationally locked manner to the motor shaft (11) by means of at least one drive belt (12) and changes the value of a force to be transmitted and of a rotational speed to be transmitted.Domestic electric appliance drive device according to claim 1, characterised in that the conical component (13, 24) is arranged stationary on the drive rotary shaft (14).Domestic electric appliance drive device according to claim 1 or 2, characterised in that the conical component (13, 24) has circumferentially encircling annular depressions (27, 28) arranged one behind the other for inserting the drive belt (12).Domestic electric appliance drive device according to claim 3, characterised in that the depressions (27, 28) have different diameters.Domestic electric appliance driving device according to claim 3 or 4, characterised in that the annular recesses (28) are connected to each other in such a way that they form in their entirety a spiral which circulates the conical component (13).Domestic electric appliance drive device according to claim 4 or 5, characterised in that the drive belt (12) runs through different depressions (27, 28) with different diameters during a single adjusting operation for adjusting the movable part.Domestic electric appliance drive device according to one of the preceding claims, characterised in that the drive rotary shaft (14) is displaced during an adjustment operation for adjusting the movable part (6) in its longitudinal direction (23).Domestic electric appliance drive device according to one of the preceding claims, characterised in that at least one toothed wheel (19, 20) for driving a toothed rail (6a) of a presser (6) of a door opener (5) is arranged on the drive rotary shaft (14).Domestic electric appliance drive device according to one of the preceding claims, characterised in that at least one worm wheel (18) for driving at least one gearwheel (20), which engages in a toothed rail (6a) of a presser (6) in order to convert a rotational movement (21) into a linear movement (7) of the presser (6), is arranged on the drive shaft (14).Domestic electric appliance drive device according to one of the preceding claims, characterised in that the movable part is a door opener (5) for opening a door (2) of a dishwasher (1).

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