DE102015222176A1 - A method for producing a shaft assembly for a household appliance, shaft assembly for a household appliance and household appliance for the care of laundry items - Google Patents

Abstract

The invention relates to a method for producing a shaft assembly 40 for a domestic appliance 10 for the care of laundry, in which an end portion 42 of a shaft 20 connected to a support structure formed for receiving a laundry drum 18 and a radial bearing 44 mounted on a bearing 46 of the shaft 20 and for sealing the radial bearing 44 in the region of a disposed between the end portion 42 and the bearing 46 sealing point 48 of the shaft 20, a radial shaft seal 50 is disposed, wherein a bushing 28 made of a corrosion resistant material and made corrosion resistant by a surface treatment and then at the sealing point 48th the shaft 20 is arranged. Furthermore, the invention relates to a shaft assembly 40 for a household appliance 10 and a household appliance 10 with a shaft assembly 40.

Description

The invention relates to a method for producing a shaft assembly for a household appliance for the care of laundry items and a shaft assembly for a household appliance for the care of laundry items specified in the preamble of the independent claims. Furthermore, the invention relates to a household appliance for the care of laundry with a shaft assembly ,

In household appliances for the care of laundry items, especially in front loader washing machines, usually a laundry drum is rotatably mounted on a shaft. For this purpose, usually an end region of the shaft is connected to a support structure designed for receiving the laundry drum, which is also referred to as a support star, wherein at least one radial bearing is mounted on a bearing point of the shaft. By means of the radial bearing, the shaft is mounted for example on a bearing housing.

A particular challenge is to achieve a reliable seal of the radial bearing, to prevent ingress of water, dust and detergent in the camp. It is known per se, to arrange a radial shaft seal to seal the radial bearing in the region of a arranged between the end and the bearing point sealing point of the shaft. The reliable sealing of such rolling bearings has a significant impact on the life of such household appliances.

Furthermore, there is usually still the problem that the shaft itself is exposed to water and in particular to washing liquor, at least in the region of said sealing point. Depending on the material composition of the shaft, this can lead to corrosion of the shaft, as a result, the life of the household appliance can be reduced.

It is the object of the present invention to achieve an increased service life of a domestic appliance for the care of items of laundry, which comprises a shaft arrangement with a shaft which is mounted by means of at least one radial bearing.

This object is achieved by a method for producing a shaft arrangement and by a shaft arrangement for a household appliance having the features of the independent patent claims. Advantageous embodiments with expedient and non-trivial developments of the invention are specified in the dependent claims.

In the inventive method of manufacturing a shaft assembly for a home appliance for laundry care, an end portion of a shaft is connected to a support structure configured to receive a laundry drum and a radial bearing is mounted to a bearing of the shaft. For sealing the radial bearing, a radial shaft sealing ring is arranged in the region of a sealing point of the shaft arranged between the end region and the bearing point. It is inventively provided that a liner made of a corrosion-resistant material and made corrosion resistant by means of a surface treatment and is then arranged at the sealing point of the shaft.

Thus, by means of the method according to the invention, a shaft arrangement is produced for a household appliance, in which the shaft is mounted by means of at least one radial bearing, which is arranged at a bearing point of the shaft. The shaft can be stored, for example by means of the radial bearing on a bearing housing. In order to ensure a reliable seal of the radial bearing, it is provided according to the invention to produce a bushing made of a corrosion-resistant material and to make corrosion resistant by means of a surface treatment and then to arrange the bushing at the sealing point of the shaft. The surface-treated liner is arranged in the manner at the sealing point of the shaft, that the radial shaft seal abuts the outer circumference of the bush, as a result, a particularly good sealing of the radial bearing can be achieved.

The fact that the liner is made of a corrosion-resistant material, in particular of a non-stainless steel material, a particularly cost-effective production of the shaft assembly is made possible. In order to protect the liner against corrosion, this is subjected to a surface treatment according to the invention. The surface treatment takes place in such a way that the liner has such a surface finish that a particularly good seal can be achieved by the radial shaft sealing ring resting on the outside circumference of the liner. The surface treatment of the bushing, the properties of the bushing are further adjusted so that a sufficient temperature resistance and durability of the liner can be ensured.

The invention is based on the finding that the shaft is exposed to wash liquor in particular in the region of the sealing point during operation of the household appliance. As a result, in particular the sealing point of the shaft is at risk of prematurely corroding. Since the liner is subjected according to the invention a surface treatment, by means of which this is made resistant to corrosion, the sealing point of the shaft can be particularly good Corrosion are protected, since the bushing is arranged on the outer peripheral side at the sealing point of the shaft. This makes it possible that the shaft is made of a corrosion-resistant material and this is not subjected to a surface treatment by means of which the corrosion resistance of the shaft would be produced.

The shaft can thus be made, for example, from a relatively inexpensive, non-stainless steel material and installed without further surface treatment in the shaft assembly. Because of the arranged at the sealing point of the shaft bush, the shaft in the region of the sealing point, which is usually exposed to wash liquor, are protected in a reliable manner against corrosion. This contributes to a particularly simple and inexpensive manufacture of the shaft assembly.

An advantageous embodiment of the invention provides that the liner is provided in the surface treatment with a chrome layer. As a result, a corrosion resistance of the liner can be achieved in a particularly simple and reliable manner, wherein in addition a particularly high surface quality can be achieved by the chrome plating of the liner.

Alternatively or additionally, it can also be provided that the liner is provided with a nickel and / or copper layer in the surface treatment. Depending on the procedure, it may happen that the chromium layer has a dense network of very fine cracks due to the production process. Therefore, it may happen that sufficient corrosion protection can not be effected. The nickel and / or copper layer can be provided as a kind of intermediate layers, by means of which the reliable corrosion protection can be ensured.

According to a further advantageous embodiment of the invention, it is provided that the liner is nitrocarburized in the surface treatment, whereby a nitrogen-enriched and carbon nitride layer is formed on the liner. By nitrocarburizing can be made on the one hand in a reliable way corrosion protection on the surface of the liner. On the other hand can be achieved by the Nitrocarburieren also a particularly high hardness of the liner.

In a further advantageous embodiment, it is provided that the support structure is produced by die casting, wherein at least the end portion of the shaft is encapsulated on the outer peripheral side by means of the support structure during the manufacture of the support structure for connecting the support structure with the end portion of the shaft. For example, the support structure made of aluminum can be produced by die-casting. The end region of the shaft can be arranged in the region of a cavity of a diecasting tool. Subsequently, the die casting tool is closed and the aluminum melt is injected into the cavity to produce the support structure. By encapsulating the end portion of the shaft, it can be connected to the support structure in a particularly simple and reliable manner. As a result of the integration into the die casting production method of the support structure, no further work steps are necessary to reliably connect the support structure to the end region of the shaft.

In an advantageous embodiment of the invention, it is also provided that, in addition, a part of the bushing arranged on the shaft is also encapsulated in the course of the die-casting process by means of the support structure. In other words, it can thus be provided that first the bushing is arranged at the sealing point of the shaft and only then the end portion of the shaft and a part of the bushing is encapsulated in the course of the die casting process by means of the support structure. This can be ensured in a simple manner that at the sealing point of the shaft during operation of the household appliance no wash liquor can get.

According to an alternative advantageous embodiment of the invention, it is provided that the bushing is arranged on the shaft after the end region of the shaft has been overmolded by means of the support structure. In this context, it is preferably provided that a sealing ring is arranged on the shaft between the bushing and the support structure. The sealing ring can be, for example, an O-ring, by means of which it can be ensured that no liquid gets between the bushing and the shaft.

The shaft arrangement according to the invention for a domestic appliance for the care of laundry items comprises a shaft with an end region which is connected to a support structure designed to receive a laundry drum. Furthermore, the shaft arrangement comprises a radial bearing mounted on a bearing point of the shaft, a radial shaft sealing ring being arranged in the region of a sealing point of the shaft arranged between the end region and the bearing point for sealing the radial bearing. The shaft arrangement according to the invention is characterized in that a bush made of a corrosion-resistant material and made corrosion-resistant by means of a surface treatment is arranged at the sealing point of the shaft. Advantageous embodiments of the method according to the invention are to be considered as advantageous embodiments of the shaft assembly according to the invention.

The household appliance according to the invention for the care of items of laundry comprises the shaft arrangement according to the invention or an advantageous embodiment of the shaft arrangement according to the invention.

In an advantageous embodiment of the household appliance according to the invention, it is provided that the household appliance is a front loader washing machine. A front loader washing machine is understood to mean a washing machine with a housing which has on its front side a charging opening for loading the laundry drum, wherein the laundry drum is rotatably arranged about a substantially horizontal or inclined axis of rotation. The invention is not limited to a front loading washing machine. It can also be used in so-called Topladerwaschmaschninen with a top on the housing lying feed opening and a substantially horizontal or vertical drum rotation axis.

The terms "top", "front", "horizontal", "vertical" indicate the positions and orientations given when the device is used and disposed of as intended and when an observer is standing in front of the device and looking towards the device.

Further advantages, features and details of the invention will become apparent from the following description of preferred embodiments and from the drawing. The features and feature combinations mentioned above in the description as well as the features and feature combinations mentioned below in the description of the figures and / or in the figures alone can be used not only in the respectively specified combination but also in other combinations or in isolation, without the scope of To leave invention.

The drawing shows in:

1 a schematic sectional view of a trained as Frontladerwaschmaschine household appliance;

2 a perspective view of a support structure for receiving a laundry drum of the front loader washing machine, wherein the support structure is connected to a shaft to which a bushing is attached;

3 1 is a side sectional view showing a bearing of the shaft of the household appliance, showing inter alia the arrangement of the bushing on the shaft,

4 a further side sectional view, in which the shaft connected to the support structure is shown, wherein the support structure surrounds the bushing partially outer peripheral side; and in

5 another side sectional view, in which an alternative embodiment is shown, in which the bushing is arranged completely outside of the support structure and rests against this.

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

In 1 is a longitudinal sectional view of a front loader washing machine 10 trained household appliance for the care of laundry items shown. The front loader washing machine 10 includes a housing 12 in which a vibrating system 14 is arranged. The vibration system 14 includes a tub 16 the front loader washing machine 10 , In addition, the front loader washing machine includes 10 a laundry drum 18 in the embodiment shown here about an axis A, which is substantially horizontal and thus in the longitudinal direction x of the front loader washing machine 10 is oriented, is rotatably mounted.

The laundry drum 18 is designed to hold laundry and from the tub 16 surround. The laundry drum 18 is about a wave 20 whose axis is also oriented in the longitudinal direction x and coaxial with the axis A, rotatably mounted. To drive the laundry drum 18 can be a pulley 22 and a belt provided by a motor 26 , For example, in the form of an electric motor, are driven. The vibration system 14 also includes feathers 28 and at least one shock absorber 30 ,

The front loader washing machine 10 includes a support structure for the tub 16 Serving star 32 , Furthermore, the front loader washing machine 10 one as a support structure for the laundry drum 18 Serving star 34 on. How to recognize, is the star 34 for the laundry drum 18 viewed in the direction of the axis A behind a rear wall 35 the laundry drum 18 arranged and with the laundry drum 18 connected. In addition, the star is 34 rotatably with the shaft 20 connected, so the laundry drum 18 itself within the means of the carrying star 32 connected tub 16 can be rotated concentrically. The carrying star 34 preferably comprises a plurality of unspecified support arms, for example, three support arms which are arranged in the direction of rotation about the axis A equidistant from each other, wherein the support arms extend radially to the axis A.

In 2 is the bearer star 34 for picking up the laundry drum 18 shown in a perspective view. The wave 20 is already with the star 34 been connected before an O-ring 36 and a liner 38 on the wave 20 to be ordered.

In 3 is the one with the wave 20 Connected baby carrier 34 shown in a side sectional view. The wave 20 and the bearer star 34 form a wave arrangement 40 out. The wave 20 is present with a gearing end region 42 with the star 34 connected. A radial bearing 44 is at a storage location 46 the wave 20 assembled. For sealing the radial bearing 44 is in the range of a sealing point 48 which extends in the axial direction between the end region 42 and the depository 46 the wave 20 located, a radial shaft seal 50 arranged. The wave 20 is by means of the radial bearing 44 on a bearing housing 52 stored, wherein the radial shaft seal 50 rotationally fixed to the bearing housing 52 is appropriate.

The related to 2 already mentioned bushing 28 is shown here only schematically. As you can see, the bushing surrounds 28 the sealing point 48 the wave 20 outer circumference. The radial shaft seal 50 lies on the outer circumference of the liner 28 so that water and washing water penetrate into the radial bearing 44 can be prevented. The bush 28 is made of a corrosion-resistant material, such as a non-stainless steel, and made corrosion resistant by means of a surface treatment. Because the corrosion-resistant liner made 28 the wave 20 in the area of the sealing point 48 surrounds the outer circumference and the radial shaft seal 50 sealing on the liner 28 is applied, can prevent the shaft 20 Water and wash liquor is exposed.

When making the shaft assembly 40 becomes the end area 42 the wave 20 with the to pick up the laundry drum 18 trained star 34 connected, with the radial bearing 44 at the depository 46 the wave 20 is mounted. For sealing the radial bearing 44 is in the area of the sealing point 48 the wave 20 on the bearing housing 52 the radial shaft seal 50 appropriate. As already mentioned, the liner is 28 made of a corrosion-resistant material and made corrosion-resistant by means of a surface treatment, before this subsequently at the sealing point 48 the wave 20 is arranged so that the radial shaft seal 50 on the outer circumference of the liner 28 is applied. Because of the in 3 Shaft arrangement shown 40 It can be ensured that no wash liquor and no other liquids to the shaft 20 can reach the shaft 20 themselves from a relatively inexpensive corrosion-resistant material, for example, made of a non-stainless steel. A surface treatment to achieve corrosion resistance of the shaft 20 can be omitted.

The bush 28 can be provided in the surface treatment, for example, with a chrome layer. Alternatively or additionally, it may also be provided that the liner 28 is provided in the surface treatment with a nickel and / or copper layer. In particular, in a combination of application of a chromium layer and a nickel and / or copper layer, a particularly high surface quality of the bushing 28 and a particularly high corrosion resistance of the liner 28 be achieved. Alternatively or additionally, it is also possible that the bushing 28 nitrocarburized, creating a nitrogen and carbon enriched nitriding layer on the liner 28 is trained. For one, the liner 28 be made corrosion resistant by the nitrocarburizing. On the other hand, the surface hardness of the liner 28 be increased considerably.

In 4 is another embodiment of the shaft assembly 40 shown in a schematic side sectional view. As can be seen in the case illustrated here, the carrying star surrounds 34 a part of the liner 28 outer circumference. The carrying star 34 can be made for example in a die-casting process. To connect the star 34 with the end area 42 the wave 20 becomes the end area 42 the wave during the manufacture of the supporting star 34 , ie during the die-casting process, on the outer peripheral side by means of the supporting star 34 molded. In the in 4 shown embodiment of the shaft assembly 40 will also be part of the wave 20 arranged bushing 28 in the course of the die casting process also by means of the supporting star 34 with overmoulded. During the production of the carrying star 34 So this is in the same process step with the end 42 and a part of the socket 28 connected.

In 5 is an alternative embodiment of the shaft assembly 40 shown in a schematic side sectional view. In order to produce the embodiment shown here, first the end region 42 the wave 20 by means of the carrying star 34 overmoulded, as a result the end area 42 the wave 20 with the star 34 is connected. Only after that is it related to 2 already mentioned O-ring 36 over the wave 20 slipped up until this frontal on the carrying star 34 is applied. In addition, the liner made corrosion resistant by the surface treatment becomes 28 also only after the encapsulation of the end area 42 the wave 20 with the star 34 on the wave 20 slipped.

By the explained method for producing the shaft assembly 40 and by the described shaft arrangement 40 can be ensured in a simple and inexpensive way that the radial bearing 44 is protected from moisture. In addition, the shaft arrangement 40 be made particularly inexpensive, since neither the liner 28 still the wave 20 must be made of a corrosion resistant material. Nevertheless, due to the explained manufacturing process and the nature of the shaft assembly 40 prevents the liner 28 and the wave 20 roast.

LIST OF REFERENCE NUMBERS

10

 Front Load Washer

12

 casing

14

 oscillating system

16

 tub

18

 washing drum

20

 wave

22

 pulley

24

 belt

26

 engine

28

 feather

30

 damper

32

 support star

34

 support star

35

 rear wall

36

 O-ring

38

 liner

40

 shaft assembly

42

 end

44

 radial bearings

46

 depository

48

 sealing point

50

 Radial shaft seal

52

 bearing housing

A

 axis

x

 longitudinal direction

z

 vertical direction

Claims (12)

Method for producing a shaft arrangement ( 40 ) for a household appliance ( 10 ) for the care of laundry items, in which an end area ( 42 ) of a wave ( 20 ) with a for receiving a laundry drum ( 18 ) formed support structure ( 34 ) and a radial bearing ( 44 ) at a depository ( 46 ) the wave ( 20 ) and for sealing the radial bearing ( 44 ) in the region of one between the end region ( 42 ) and the depository ( 46 ) arranged sealing point ( 48 ) the wave ( 20 ) a radial shaft sealing ring ( 50 ), characterized in that a bushing ( 28 ) made of a corrosion-resistant material and made corrosion-resistant by means of a surface treatment and then at the sealing point ( 48 ) the wave ( 20 ) is arranged. Method according to claim 1, characterized in that the shaft ( 20 made of a non-corrosive material and without undergoing a surface treatment by means of which the corrosion resistance of the shaft ( 20 ), in the shaft arrangement ( 40 ) is installed. Method according to claim 1 or 2, characterized in that the bushing ( 28 ) is provided with a chromium layer during the surface treatment. Method according to one of the preceding claims, characterized in that the bushing ( 28 ) is provided in the surface treatment with a nickel and / or copper layer. Method according to one of the preceding claims, characterized in that the bushing ( 28 ) is nitrocarburized during the surface treatment, whereby a nitrogen and carbon-enriched nitride layer on the liner ( 28 ) is formed. Method according to one of the preceding claims, characterized in that the supporting structure ( 34 ) is produced by die-casting, wherein for joining the support structure ( 34 ) with the end region ( 42 ) the wave ( 20 ) at least the end region ( 42 ) the wave ( 20 ) during the manufacture of the support structure ( 34 ) outside circumference by means of the support structure ( 34 ) is overmoulded. A method according to claim 6, characterized in that also a part of the on the shaft ( 20 ) arranged bushing ( 28 ) in the course of the die-casting process also by means of the support structure ( 34 ) is overmoulded. Method according to claim 6, characterized in that the bushing ( 28 ) on the shaft ( 20 ) is arranged after the end region ( 42 ) the wave ( 20 ) by means of the supporting structure ( 34 ) has been overmoulded. Method according to claim 8, characterized in that between the bushing ( 28 ) and the supporting structure ( 34 ) a sealing ring ( 36 ) on the shaft ( 20 ) is arranged. Shaft arrangement ( 40 ) for a household appliance ( 10 ) for the care of laundry items, in which an end area ( 42 ) of a wave ( 20 ) with a for receiving a laundry drum ( 18 ) formed support structure ( 34 ) and a radial bearing ( 44 ) at a depository ( 46 ) the wave ( 20 ) and for sealing the radial bearing ( 44 ) in the region of one between the end region ( 42 ) and the depository ( 46 ) arranged sealing point ( 48 ) the wave ( 20 ) a radial shaft sealing ring ( 50 ), characterized in that a bushing made of a corrosion-resistant material and made corrosion-resistant by means of a surface treatment ( 28 ) at the sealing point ( 48 ) the wave ( 20 ) is arranged. Household appliance ( 10 ) for the care of laundry items with a shaft arrangement ( 40 ) according to claim 10. Household appliance ( 10 ) according to claim 11, characterized in that the domestic appliance ( 10 ) is a front loader washing machine or Topladerwaschmaschine.

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