EP3663453A1 - Domestic appliance for the care of laundry items with a belt disc to which a spring element is attached - Google Patents

Abstract

The invention relates to a household appliance for the care of laundry, with a laundry drum which comprises a drive shaft (4) and with a pulley (8) which can be rotated about an axis of rotation (A) of the pulley (8) by means of a belt drive of the household appliance. The pulley (8) is connected to the drive shaft (4) in a rotationally fixed manner, and a hub (9) of the pulley (8) has at least one form-locking element (10) which is connected to at least one corresponding form-fitting element (10) of the drive shaft (4) Intervention is. The at least one form-locking element (10) of the hub (9) extends in the direction of the axis of rotation (A) into a region (16) of the hub (9) in which a spring element (15) is arranged on the hub (9).

Description

The invention relates to a household appliance for the care of laundry, with a laundry drum, which comprises a drive shaft, and with a pulley. The belt pulley can be rotated about an axis of rotation of the belt pulley by means of a belt drive of the household appliance. The pulley is non-rotatably connected to the drive shaft. A hub of the pulley has at least one form-fit element which engages with at least one corresponding form-fit element of the drive shaft.

Such a household appliance is for example in the EP 2 557 219 A1 described. Here, a drive shaft has a toothing which engages in a corresponding toothing which is formed in a hub of a pulley.

Furthermore, in the case of a household appliance which is designed, for example, as a front-loading washing machine, the pulley in the region of its hub can have an insert which is formed from a steel and thus from a firmer material than the rest of the pulley. Via this insert which provides the hub or this insert made of steel, a torque is transmitted to the drive shaft when the pulley is driven, that is to say when the pulley is rotated about its axis of rotation, by means of a toothing of the steel insert.

The fact that the provision of the steel insert in the pulley is associated with increased effort and costs is to be considered a disadvantage here.

The object of the present invention is therefore to create a household appliance for the care of laundry items in which a torque can be transmitted from the pulley to the drive shaft in a particularly low-effort manner.

This object is achieved by a household appliance with the features of patent claim 1. Advantageous refinements with expedient developments of the invention are specified in the dependent claims.

The household appliance according to the invention for the care of laundry items has a laundry drum which comprises a drive shaft and a belt pulley which can be rotated about an axis of rotation of the belt pulley by means of a belt drive of the household appliance. The pulley is non-rotatably connected to the drive shaft. A hub of the pulley has at least one form-fit element which engages with at least one corresponding form-fit element of the drive shaft. Here, the at least one form-locking element of the hub extends in the direction of the axis of rotation into a region of the hub in which a spring element is arranged on the hub. The at least one form-locking element of the hub and thus of the pulley therefore has a particularly large length in the direction of the axis of rotation. This allows torque to be transmitted from the belt pulley driven by the belt drive to the drive shaft. A steel insert can still be dispensed with. This makes the transmission of the torque from the pulley to the drive shaft particularly easy.

By providing the spring element arranged on the hub, a preload of a bearing element can be achieved, which serves to mount the drive shaft in a bearing housing of the household appliance. In particular, an employed mounting of the drive shaft of the laundry drum can be realized. The drum bearing, which encompasses the spring element, can be used to increase the bearing service life and the bearing rigidity.

This is based on the knowledge that during operation of the laundry drum, for example during a washing process and / or during a spinning process and / or during a drying process, the items of laundry are distributed randomly in the laundry drum. This results in imbalances, which represent a great mechanical load for the household appliance and in particular for the drum storage, that is to say the storage of the laundry drum.

With the constructive embodiment of the household appliance described here, in which the spring element is arranged on the hub, it is not only possible to reduce general bearing noises which result from the rotation of the laundry drum about its axis of rotation, this axis of rotation of the laundry drum preferably with the The axis of rotation of the pulley coincides. Rather, special bearing noises can also be eliminated, which can only occur when the laundry drum is rotating when certain boundary conditions exist, for example in the form of a clacking or the like.

In particular, by providing the at least one form-locking element, which is formed in the hub of the pulley, and thus by dispensing with an insert made, for example, of steel, cost savings can be achieved and an effort to provide the pulley can be reduced.

Furthermore, it is possible to arrange the spring element preassembled on the hub. As a result, the pulley with the spring element arranged on the hub can be provided as a preassembled structural unit, for example by a supplier. This reduces the effort involved in a final assembly of the household appliance, since the spring element does not also have to be assembled as part of this final assembly.

The provision of the form-locking element of the at least one hub, which is comparatively long in the direction of the axis of rotation of the pulley, makes it particularly easy to mount the pulley on the drive shaft in order to connect the pulley to the drive shaft in a form-fitting and rotationally fixed manner. Because the comparatively large length of the form-fitting element of the hub ensures good guidance of the pulley along the drive shaft when the hub is plugged onto the drive shaft. Tilting of the pulley, that is to say a deviation from a right-angled alignment of the pulley with respect to the drive shaft, can be particularly largely prevented in this way. This is also conducive to the good transmission of the torque from the pulley to the drive shaft.

Finally, due to the attachment of the spring element to the hub, it can be determined particularly easily, for example via a visual inspection, whether the spring element is installed or not. Because the spring element arranged on the hub is good too see, for example, by a mechanic or by a person who is concerned with the visual inspection, in particular at the incoming goods and / or by an optical detection device such as a camera.

The area of the hub in which the spring element is arranged is preferably designed as a hollow cylindrical shoulder of the pulley. Here, the spring element is arranged on the outside of the hollow cylindrical shoulder. In this way, a form-locking element of the hub that is particularly long in the direction of the axis of rotation can be realized with a comparatively low weight of the pulley. The hollow cylindrical shoulder preferably has a smaller diameter than an area of the hub adjoining the shoulder in the direction of the axis of rotation.

It has proven to be further advantageous if the at least one form-fitting element of the hub is designed in the direction of the axis of rotation over the entire length of the hub. In other words, the positive locking element of the hub then extends over the entire axial length of the hub. As a result, the available axial length of the hub can be used particularly well for transmitting the torque from the pulley to the drive shaft.

The spring element preferably applies pressure to a bearing element, by means of which the drive shaft is rotatably mounted about the axis of rotation in a bearing housing of the household appliance. When the household appliance is designed as a washing machine or washer-dryer, the bearing housing can be formed, for example, by a tub of the household appliance. By applying pressure to the bearing element, the bearing element can be preloaded. And due to the preload, an improved absorption of axial forces by the bearing elements can be achieved, which serve to support the drive shaft in the bearing housing. In particular, an employed support bearing can be realized in the O orientation of the pressure lines or force flow lines running through the bearing elements, that is, an O arrangement of the employed bearing.

At least one radial projection is preferably formed in the area of the hub, which secures the spring element against loosening from the hub. In this way it can be ensured that the spring element, once attached to the hub, is also attached the hub remains. This simplifies the handling of the pulley, since with this handling it is then not necessary to ensure that the spring element is not accidentally detached from the hub.

The at least one radial projection can in particular be formed on an end edge of the region of the hub, for example by upsetting the material of the hub or deforming or shaping the material of the hub in the radial direction.

The spring element is preferably designed as a wave spring which has at least one wave crest and at least one wave trough in the circumferential direction. By means of such an, in particular annular, wave spring, a preloading of at least one bearing element, which serves to support the drive shaft, can be achieved in a functionally reliable manner even with comparatively little available space.

The at least one radial projection is preferably arranged in the circumferential direction of the wave spring in the region of the at least one wave valley. Because then when securing the wave spring to the hub, the at least one radial projection can be easily formed without this formation being impaired by the wave spring. This facilitates the captive mounting of the spring element on the hub.

It has proven to be further advantageous if the spring element has at least one first structural element which engages with at least one second structural element formed on the hub. Such an engagement of the structural elements with one another makes it very easy to predefine a positional orientation of the spring element on the hub. On the one hand, this facilitates the assembly or attachment of the spring element to the hub. On the other hand, it can thus be ensured in a simple manner that by reshaping or upsetting the material of the hub in areas not affected by the spring element, the spring element can be arranged captively on the hub.

One of the structural elements can be formed very simply and with little effort as a radial projection and the other of the structural elements as a depression, for example in the form of a groove.

The structural elements preferably predetermine an installed position of the spring element in which the spring element is arranged on the hub. In this way, it can be ensured according to the Poka Yoke principle that the spring element can only be attached to the hub in exactly one, predetermined manner. This makes the assembly of the spring element particularly reliable and easy.

At least the hub of the pulley is preferably formed from an aluminum alloy. On the one hand, this is inexpensive and, on the other hand, it is advantageous with regard to the weight of the pulley. This is especially true when not only the hub but the entire pulley is made of aluminum alloy.

The mutually corresponding positive locking elements of the hub and the drive shaft are preferably designed as teeth of a fit toothing. This is also conducive to a good transmission of the torque from the pulley to the drive shaft, in particular if the spline is designed as a serration.

With information such as "top", "bottom", "front", "rear," horizontal "," vertical "," depth direction "," width direction "," height direction "and the like are those with intended use and arrangement of the household appliance and given positions and orientations given to an observer standing in front of the household appliance and looking in the direction of the household appliance.

The features and combinations of features mentioned above in the description and the features and combinations of features mentioned below in the description of the figures and / or shown alone in the figures can be used not only in the combination indicated in each case, but also in other combinations or on their own, without the scope of Leaving invention. Embodiments are thus also to be regarded and encompassed by the invention, which are not explicitly shown or explained in the figures, but are separated by Combinations of features emerge from the explanations given and can be generated. Designs and combinations of features that do not have all the features of an originally formulated independent claim are therefore also to be regarded as disclosed. In addition, versions and combinations of features, in particular those explained above, are to be regarded as disclosed which go beyond or differ from the combinations of features set out in the references of the claims.

Fig. 1

stark schematisiert und in einer vertikalen Schnittdarstellung ein Haushaltsgerät zur Pflege von Wäschestücken, bei welchem über eine Riemenscheibe ein Drehmoment auf eine Antriebswelle einer Wäschetrommel übertragen werden kann;

Fig. 2

ausschnittsweise und in einer Schnittdarstellung einen Teilbereich der Riemenscheibe und der Antriebswelle;

Fig. 3

ausschnittsweise die Riemenscheibe gemäß Fig. 2 in einer Perspektivansicht;

Fig. 4

ausschnittsweise die Riemenscheibe gemäß Fig.2 in einer weiteren Perspektivansicht; und

Fig. 5

in einer vergrößerten Detaildarstellung einen Ausschnitt der Riemenscheibe gemäß Fig. 2 im Bereich ihrer Nabe.

Further advantages, features and details of the invention result from the claims, the following description of preferred embodiments and with reference to the drawings. Show:

Fig. 1

highly schematic and in a vertical sectional view of a household appliance for the care of laundry items, in which a torque can be transmitted to a drive shaft of a laundry drum via a pulley;

Fig. 2

a section and a sectional view of a portion of the pulley and the drive shaft;

Fig. 3

sections of the pulley according to Fig. 2 in a perspective view;

Fig. 4

sections of the pulley according to Fig. 2 in a further perspective view; and

Fig. 5

in an enlarged detail view of a section of the pulley Fig. 2 in the area of their hub.

In Fig. 1 a household appliance 1 is shown in a schematic representation, which is designed for the care of laundry items. The household appliance 1 can be designed, for example, as a washing machine, a dryer or a washer-dryer. The household appliance 1 comprises an outer housing 2, in which a laundry drum 3 is rotatably mounted about an axis of rotation A. For example, a drive shaft 4 can be used for this or drum shaft of the laundry drum 3 in a bearing housing of a tub (not shown) of the household appliance 1.

To drive the drive shaft 4, that is to say to rotate the drive shaft 4 and with it the washing drum 3 about the axis of rotation A, the household appliance 1 has a belt drive 5, which comprises a motor 6 and a belt 7. During operation of the motor 6, the belt 7 sets a belt pulley 8 in a rotational movement about the axis of rotation A. A hub 9 is formed in one piece with the belt pulley 8 and is connected to the drive shaft 4 in a form-fitting and rotationally fixed manner.

For this purpose, for example, corresponding interlocking elements of the hub 9 on the one hand and the drive shaft 4 on the other hand can be designed as teeth 10 of a serration 11, which in FIG Fig. 2 is indicated schematically. The teeth 10 of the hub 9 are approximately in Fig. 3 and in Fig. 4 can be seen better, only some of the teeth 10 being provided with a reference symbol here.

In Fig. 2 is the drive shaft 4 without one in Fig. 1 shown rear wall 12 of the laundry drum 3, which is rotatably connected to the drive shaft 4. In contrast, are in Fig. 2 A bearing arrangement, via which the drive shaft 4 is rotatably mounted about the axis of rotation A, shows a first bearing element, in the present case designed as a roller bearing 13, and a second bearing element, also in the present case also designed as a roller bearing 14. The two roller bearings 13, 14 preferably provide an employed support bearing for the drive shaft 4, in particular an O arrangement of the two employed roller bearings 13, 14 can be realized.

A spring element 15 is provided for prestressing the roller bearing 13 closer to the pulley 8 Fig. 2 is shown schematically. In particular from the representations in 3 and 4 it can be seen that the spring element 15 can be configured here, for example, as a wave spring.

In the present case, the spring element 15 is arranged on the hub 9. Out Fig. 2 it can also be seen that the teeth 10 of the serration 11 of the hub 9 extend into a region of the hub 9 in which the spring element 15 is arranged on the hub 9. Especially when looking at Fig. 2 With Fig. 3 it can be seen that this area of the hub 9 is designed as a hollow cylindrical shoulder 16 of the pulley 8, on the outside of which the spring element 15 is arranged. This shoulder 16 is followed in the direction of the axis of rotation A by a likewise hollow cylindrical section 27 of the hub 9, which has a larger outer diameter than the shoulder 16. From this hollow cylindrical section 27, struts 28 of the pulley 8 extending in one piece with this section 27 extend in the present case in a radial direction (compare in particular Fig. 4 ).

The serration 11 of the hub 9 thus extends over a comparatively large length of the hub 9 in the direction of the axis of rotation A. In particular, the serration 11 of the hub 9 extends to a first step 17 formed in the drive shaft 4. In a region between this first Step 17 and a further or second step 18 of the drive shaft 4, the drive shaft 4 has a larger outer diameter than in the area in which the serration 11 of the drive shaft 4 is formed. The first roller bearing 13 is also arranged in the area between the first stage 17 and the second stage 18. The hollow cylindrical shoulder 16 formed on the pulley 8 preferably abuts the first step 17. Furthermore, an outer side of the shoulder 16 preferably ends flush with a longitudinal section of the drive shaft 4 formed between the first step 17 and the second step 18.

In the present case, when the pulley 8 is connected to the drive shaft 4, the spring element 15 acts on an inner ring 19 of the first roller bearing 13 with a pressure acting in the direction of the axis of rotation A. As a result, the first roller bearing 13 is preloaded.

Due to the long design of the serration 11 in the direction of the axis of rotation A, a good transmission of torque from the pulley 8 to the drive shaft 4 is ensured without an insert or insert made of steel needing to be arranged in the pulley 8, which has a spline, especially serration. As a result, the pulley 8 is particularly simple. In particular, the pulley 8 and the hub 9 formed in one piece with the pulley 8 are formed here from an aluminum alloy.

When the pulley 8 is mounted on the drive shaft 4, the drive shaft 4 is set up vertically, so that the axis of rotation A runs vertically. Then the pulley 8 is pushed onto the vertical drive shaft 4 from above and finally secured in its position, for example by means of a Fig. 2 shown screw 20. For this purpose, the screw 20 is screwed into a bore which is formed in the drive shaft 4. The spring element 15 can indeed be placed on the end area of the drive shaft 4 having the serration 11 when the pulley 8 is mounted on the drive shaft 4. However, for a reliable assembly of the spring element 15, it is advantageous to pre-assemble the spring element 15 on the pulley 8.

For this purpose, the spring element 15 can be arranged on the outside of the shoulder 16 designed in the manner of a hollow cylindrical extension and secured against losing or loosening from the hub 9. For example, an end edge 21 of the shoulder 16 can be deformed at at least one point. As a result, at least one radial projection 22 is formed in the shoulder 16.

Two such radial projections 22 are shown here by way of example. However, the spring element 15 can also be secured against the detachment from the hub 9 over the entire circumference of the shoulder 16, for example by upsetting the material of the shoulder 16. More than the two radial projections 22 shown here by way of example can also be formed, which are preferably evenly spaced apart from one another in the circumferential direction. Such a deformation of the shoulder 16 or such an upsetting of material, in particular in the region of the edge 21 of the shoulder 16, can be accomplished, for example, by means of a press or the like.

On the one hand, on the spring element 15 and on the shoulder 16 of the pulley 8, on the other hand, shaped elements or structural elements are formed which are in engagement with one another. For example, such a structural element formed on the hub 9 can be designed as a depression or as a groove 23 (compare in particular Fig. 3 and Fig. 5 ). Then this is preferably Structural element provided on the spring element 15 side is designed as a projection 24 which engages in the groove 23.

In the present example, two such structural elements corresponding to one another are formed on sides of the shoulder 16 that are opposite one another with respect to the axis of rotation A. Such structural elements or shaped elements can ensure that the spring element 15 or the spring washer or wave spring is arranged in a predetermined positional orientation on the hub 9. In particular, it can thus be ensured according to the poka yoke principle that the spring element 15 can only be arranged on the hub 9 in exactly a predetermined positional orientation or installation position.

The spring element 15 designed here as a wave spring has a plurality of wave crests 25 and wave troughs 26, only a few of which are provided with a reference symbol in the figures. For example, in the case of a spring element 15 in the form of a wave spring with four wave crests 25 and four wave troughs 26, it can be ensured that the wave troughs 26 of the spring element 15 come to rest in the area of the radial projections 22 of the shoulder 16. This makes it particularly easy to secure the spring element 15 against detaching from the hub 9 by forming the projections 22. However, a larger or a smaller number than the number of wave crests 25 and wave troughs 26 shown here by way of example can also be provided. The projections 24 of the spring element 15 corresponding to the grooves 23 can also be formed in the region of a respective trough 26.

Out Fig. 4 it can be seen particularly well that the teeth 10 of the serration 11 extend in the direction of the axis of rotation A over an entire axial length of the hub 9.

Out Fig. 5 In contrast, it is clear how the structural elements in the form of the radial projections 24 engage in the structural elements in the form of the grooves 23, which are formed in the shoulder 16 of the hub 9.

Overall, the examples show how a pulley 8 formed from an aluminum alloy with an attached spring ring or spring element 15 can ensure improved storage of the washing drum 3.

Reference symbol list

1

Home appliance

2nd

Outer housing

3rd

Laundry drum

4th

drive shaft

5

Belt drive

6

engine

7

belt

8th

Pulley

9

hub

10th

tooth

11

Serration

12

Back wall

13

roller bearing

14

roller bearing

15

Spring element

16

paragraph

17th

step

18th

step

19th

Inner ring

20th

screw

21st

edge

22

head Start

23

Groove

24th

head Start

25th

Wellenberg

26

Wave trough

27th

section

28

strut

A

Axis of rotation

Claims (12)

Household appliance (1) for the care of laundry, with a laundry drum (3), which comprises a drive shaft (4), and with a pulley (8), which is driven by a belt drive (5) of the household appliance (1) about an axis of rotation (A) of the pulley (8) is rotatable, the pulley (8) being connected in a rotationally fixed manner to the drive shaft (4) and a hub (9) of the pulley (8) having at least one form-locking element (10) which is connected to at least one corresponding form-fitting element (10 ) of the drive shaft (4), characterized in that the at least one form-locking element (10) of the hub (9) extends in the direction of the axis of rotation (A) into a region (16) of the hub (9) in which a spring element (15) is arranged on the hub (9). Domestic appliance according to claim 1, characterized in that the area of the hub (9) is designed as a hollow cylindrical shoulder (16) of the pulley (8), on the outside of which the spring element (15) is arranged. Domestic appliance according to claim 1 or 2, characterized in that the at least one form-locking element (10) of the hub (9) is formed in the direction of the axis of rotation (A) over an entire length of the hub (A). Domestic appliance according to one of the preceding claims, characterized in that the spring element (15) pressurizes a bearing element (13) by means of which the drive shaft (4) is rotatably mounted about the axis of rotation (A) in a bearing housing of the domestic appliance (1). Domestic appliance according to one of the preceding claims, characterized in that in the area (16) of the hub (9), in particular on an end edge (21) of the area (16), at least one radial projection (22) is formed, which is the spring element (15) secures against loosening from the hub (9). Domestic appliance according to one of the preceding claims, characterized in that the spring element (15) is designed as a wave spring which has at least one wave crest (25) and at least one wave trough (26) in the circumferential direction. Domestic appliance according to claim 5 and 6, characterized in that the at least one radial projection (22) is arranged in the circumferential direction of the wave spring in the region of the at least one wave valley (26). Domestic appliance according to one of the preceding claims, characterized in that the spring element (15) has at least one first structural element (24) which engages with at least one second structural element (23) formed on the hub (9). Domestic appliance according to claim 8, characterized in that one of the structural elements is designed as a radial projection (24) and the other of the structural elements as a recess (23). Household appliance according to claim 8 or 9, characterized in that the structural elements (23, 24) predetermine an installed position of the spring element (15) in which the spring element (15) is arranged on the hub (9). Household appliance according to one of the preceding claims, characterized in that at least the hub (9) of the pulley (8), in particular the entire pulley (8), is formed from an aluminum alloy. Household appliance according to one of the preceding claims, characterized in that the mutually corresponding positive locking elements of the hub (9) and the drive shaft (4) are designed as teeth (10) of a spline, in particular a serration (11).

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