CN113802334A - Drum housing for a domestic washing appliance and domestic washing appliance - Google Patents

Abstract

The invention relates to a drum housing (2) for a domestic washing appliance (101), having a rear drum housing section (1), the drum housing section (1) having at least: the bearing cartridge comprises a hollow cylindrical sleeve region (5), a support structure (106) extending radially from the sleeve region (5), and a base body (4) connected to the support structure (106) on the front side and having an end wall (3) arranged annularly around the sleeve region (5), wherein the end wall (3) is spaced apart from the sleeve region (5), and a bearing bush (108) fixedly surrounded on the outside by the sleeve region (5), wherein an open region (6) between the sleeve region (5) and the end wall (3) is covered by a cover (7-9) connected to the end wall (3) and the sleeve region (5). A domestic washing appliance (101) has such a drum housing (2). The invention can be advantageously applied in particular to washing machines and washer-dryers.

Description

Drum housing for a domestic washing appliance and domestic washing appliance

Technical Field

The invention relates to a drum housing for a domestic washing appliance, having a rear-facing drum housing section

Wherein the drum shell segment comprises at least: base ofA body having a hollow-cylindrical sleeve region, a support structure extending radially (abgehend) from the sleeve region, an end wall arranged annularly around the sleeve region and arranged (ansetzen) on the support structure on a front side; a bearing bush (Lagerbuchse) which is fixedly surrounded on the outside by the sleeve region. The invention also relates to a domestic washing appliance having such a drum housing. The invention is particularly advantageously applicable to domestic washing appliances in the form of washing machines and washer-dryers.

Background

EP 3330428 a1 discloses a drum housing for a domestic washing appliance, having a rear or rear drum housing section, wherein the drum housing section has: at least one base body made of plastic, which has a hollow cylindrical sleeve region at a central location, a support structure extending radially from the sleeve region, and an end wall arranged annularly around the sleeve region, which is arranged on the front side on the support structure; a bearing bush ("bearing shell") made of metal, which is fixedly surrounded on the outside by the sleeve region. The bearing bush serves for the passage of a drive shaft for rotating a laundry drum received in the drum housing. The bearing bush is surrounded laterally and on its edge on the end side by a bush region and is therefore fixedly connected to the rear drum shell section. In particular, the end wall is annularly arranged on the edge of the sleeve region on the front side. In the case of use in a washer dryer, the rear drum shell section furthermore has an air channel which leads through the base body and is laterally delimited by the base body and at least one cover (Deckel) which is placed on the base body.

The production of the rear drum shell section is carried out by means of an injection molding method in which the bearing bush is extruded or injection-molded on the outside together with the main body. For this purpose, the bearing bush can be introduced, for example, into an injection molding tool for producing the base body.

When the base body cools, it is disadvantageous that contact losses can occur between the sleeve region and the bearing bush.

Disclosure of Invention

The invention aims to provide the following steps: the disadvantages of the prior art are at least partially overcome and, in particular, a possibility is provided which can be implemented simply and inexpensively, providing a reliable connection between the base body of the rear drum shell segment and the bearing bushing inserted (in particular injected) into the base body.

This object is achieved according to the features of the independent claims. Advantageous embodiments are the subject of the dependent claims, the description and the figures.

This object is achieved by a drum housing for a domestic washing appliance having a rear drum housing section, wherein the drum housing section has at least:

-a substrate having:

a hollow cylindrical sleeve region which is,

a support structure extending in a radial direction from the sleeve region, and

an end wall arranged annularly around the sleeve region, which is arranged on the front side on the support structure, and

a bearing bush fixedly surrounded on the outside by the sleeve region,

wherein the content of the first and second substances,

the end wall is spaced from the sleeve region, and

the open area between the sleeve region and the end wall is covered by a cover (Abdeckung) connected to the end wall and to the sleeve region.

Such a drum shell yields the advantage that: contact losses between the sleeve region and the bearing bush can be avoided. This advantage is based on the recognition that: when the conventional base body cools, it is disadvantageous that material shrinkage occurs in the region of the end wall. The end wall thereby pulls apart (deforms) the edge of the sleeve region on the front side in the lateral direction, so that a loss of contact between the sleeve region and the bearing cartridge can occur there. The open region of the drum shell according to the invention between the sleeve region and the end wall (which open region thus results in the end wall now no longer directly transitioning into the sleeve region or no longer resting on the sleeve region) prevents: the sleeve region is warped/deformed in the axial direction when the end wall is contracted (Verzug). This again prevents: the plastic on the front edge of the sleeve region is pulled off the bearing bush (Abziehen).

A further advantage is that a largely symmetrical geometry of the sleeve region in the axial direction (in which the geometry is identical at both ends of the sleeve) is also produced, which leads to a more uniform pressure distribution during cooling of the material. This in turn reduces the effect of edge thinning on the front side of the sleeve region.

Since the drum housing also serves to enclose water, lye and moist air during the laundry treatment process, the open area is covered by the cover (in order not to impede the above-mentioned function of the drum housing). Since only a small to almost negligible mechanical load or no mechanical load occurs in the region of the cover (more precisely also during operation of the domestic washing appliance), additional advantages result: the cover can be produced from a particularly inexpensive material, which can be different from the material of the base body.

The domestic washing appliance may be a washing machine or a combined washing/drying appliance ("washer-dryer").

The drum housing typically receives a rotatable laundry drum in a domestic washing appliance. The laundry drum can be rotated by means of a drive shaft guided by a bearing bush, while the drum housing is arranged non-rotatably (or fixedly) in the domestic washing appliance. In particular, the laundry drum can be loaded with laundry on the front side, wherein such household washing appliances are generally referred to as "front loaders". However, the invention is not limited to front loaders, but can also be used, for example, in household washing appliances equipped with a laundry drum that can be loaded from above (so-called "top loaders").

For simple installation of the laundry drum, the drum housing is typically constructed in two parts: a drum housing section on the front or front side and a rear or rear drum housing section, which are assembled in one piece after the laundry drum has been loaded. Here, the terms "front" or "front side" and "rear" or "rear" relate to typical arrangements in front loaders: the front or front side of the front loader faces the user. In the case of use in a top loader, the arrangement at "front"/"front side" is equivalent to the arrangement at "upper", and the arrangement at "rear"/"rear" is equivalent to the arrangement at "lower". Within the framework of the present description of the invention, the terminology used in connection with front loaders is used, even if the invention is not limited thereto.

The basic body defines the basic shape of the rear drum shell section. The base body is made of plastic, in particular thermoplastic. The substrate is in particular an injection-molded component.

The sleeve region surrounds the outer circumferential surface of the bearing bush. The sleeve region advantageously extends over the annular end face of the bearing cartridge, since this reliably prevents the bearing cartridge from slipping out of the sleeve region by means of a form-locking connection. The bearing bush is fixedly surrounded by the sleeve region on the outside, which includes: the sleeve region and the bearing bush are not rotatable relative to one another (or are not provided for mutual rotation).

The support structure extends radially from the sleeve region with reference to a longitudinal axis of the sleeve region. The support structure is used for: supporting an end wall arranged on the support structure on the front side (or in front). An embodiment that is advantageous for a lightweight, but stable construction is: the support structure is a ribbed and/or a grid structure.

The end walls are arranged in an annularly spaced manner around the sleeve region. Such end walls are typically at least substantially vertically oriented. The end wall is spaced apart (radially) from the sleeve region, which includes, inter alia: the associated open area (or radial gap) is annular.

One development is that the end wall transitions at its (in the case of a view on the front side), typically circular, outer edge into a hollow cylindrical side wall of the base body, which projects forward. This results in the advantage that: the connection to a matching drum shell section on the front side is facilitated. The base body then has a pot-like or barrel-like basic shape. This can also be expressed as: the base body then has a hollow cylindrical basic shape with an end face in which (in particular centrally) a sleeve region is arranged.

One embodiment provides that the end wall has a channel-like recess which is partially covered on the front side by means of a cover and is formed integrally with the covering. This achieves the advantage that: only one component (i.e. the integral cover/lid combination) needs to be mounted on the base. This makes manufacturing, warehouse management, and handling easy. This configuration is particularly advantageous for a washer dryer, since the process air to be dried can be conducted out of the drum housing via the air channel.

In one embodiment, the channel-like recess is arranged with the cover as a cooling channel for the air escaping from the drum shell. This results in the advantage that: a separate condenser can be dispensed with or can be implemented at least comparatively small. One development is that the laundry dryer has a heat pump. Under the frame of current domestic washing appliances, the air channel can be constructed substantially similarly to EP 3330428 a 1. The cover part can be constructed, for example, in the form of a ring segment.

In one embodiment, the inner edge of the channel-like recess merges into the outer edge of the opening region. This achieves the advantage that: the cover/covering combination can be designed to be particularly durable (in particular without connecting webs).

One configuration is that the cover or, if present, the cover/cover combination is welded (e.g., laser welded) to the base. This achieves a particularly reliable and tight connection. However, this connection can also be made, for example, by gluing or the like.

In one embodiment, the base body is made of a first plastic material and the cover part is made of a second plastic material different from the first plastic material. Advantageously, such plastics can be selected in a targeted manner: the plastic is particularly mechanically advantageous and/or particularly inexpensive for the purpose specified.

In one embodiment, the cover comprises or is made of polypropylene. This material is particularly inexpensive andand is sufficiently stable mechanically and chemically for the purpose of masking. In one development, the covering part is made of PP-TV or calcium carbonate (CaCO)₃) Filled polypropylene.

The object is also achieved by a domestic washing appliance comprising a drum shell as described above with a rear drum shell section. The domestic washing appliance can be constructed similarly to the drum housing described above and has the same advantages.

In particular, a domestic washing appliance comprises a rotatable laundry drum which is accommodated in a drum housing and which can be rotated by means of a drive shaft guided by a bearing bush.

Drawings

The above-described features, characteristics and advantages of the present invention, as well as the manner and method of how they are accomplished, will become clearer and more clearly understood in connection with the following illustrative description of embodiments, which are explained more thoroughly in connection with the drawings. The figures show:

fig. 1 shows a sketch of a rear drum shell section according to a first embodiment in a side view as a sectional illustration; and

figure 2 shows a sketch of a rear drum shell section according to a first embodiment in a front view;

figure 3 shows a sketch of a rear drum shell section according to a second embodiment in a front view;

fig. 4 shows an exploded view of a conventional rear drum shell section of a drum shell for a domestic washing appliance in an oblique view;

FIG. 5 shows a front view of a conventional rear drum shell section;

FIG. 6 shows a rear view of a conventional rear drum shell section; and

fig. 7 shows a sketch of a conventional rear drum shell section in a side view as a sectional illustration.

Detailed Description

Fig. 4 shows an exploded view of a conventional rear drum housing section 103 of a drum housing 102 for a domestic washing appliance 101 in an oblique view. Fig. 5 shows a front view of a conventional rear drum shell section 103. Fig. 6 shows a rear view of a conventional rear drum shell section 103. Fig. 7 shows a simplified sketch of a conventional rear drum shell section 103 in a side view as a sectional illustration. The conventional rear drum shell segment 103 is, for example, a simplified embodiment of the rear drum shell segment shown in EP 3330428 a1 and can be developed in a similar manner to EP 3330428 a1 if required.

The rear drum shell segment 103 has a base body 104 made of plastic, which base body 104 has: a hollow cylindrical sleeve region 105; a ribbed support structure 106 extending radially from the sleeve region 105 (see fig. 6); an end wall 107 arranged annularly around the sleeve region 105, which is arranged on the front side on the support structure 106. The sleeve region 105 surrounds the outside of a metal bearing bush 108 having a longitudinal axis a.

The end wall 107 has a ring-shaped, fan-shaped channel-like retraction 109, which retraction 109 is partially covered on the front side by means of a matching ring-shaped fan cover 110. The retraction 109 and the cover 110 constitute a passage (in particular a cooling passage 111) for the air L escaping from the drum shell 102. For this purpose, the cover 110 does not completely cover this channel-like recess 109, but rather leaves an opening 112 via which the air L can enter into the cooling channel 111 and can exit again via a corresponding opening 113 in the end wall 107.

Furthermore, the end wall 107 merges on its radially outer edge into a forwardly projecting, hollow-cylindrical side wall 114 of the base body 104.

As is evident from fig. 7, when the conventional base body 104 cools during the injection molding process, an uneven pressure distribution is produced in the axial direction or longitudinal direction of the sleeve region 105 due to the asymmetrical attachment to the sleeve end. Furthermore, since the end wall 107 is attached to the front edge 105a of the sleeve region 105, the pulling-off of the plastic from the bearing bushing 108 is effected by deformation in the direction P1 (deformation caused by the attachment of the end wall 107).

Fig. 1 shows a sketch of a rear drum shell section 1 according to a first embodiment in a side view as a sectional illustration. Fig. 2 shows a sketch of the rear drum shell segment 1 with the cover 7 drawn apart in a front view. Instead of the rear drum housing section 103, the rear drum housing section 1 can be provided, for example, as part of a drum housing 2 installed in the domestic washing appliance 101.

The drum shell segment 1 differs from the drum shell segment 103 in that the end wall 3 of the base body 4 now no longer merges into the sleeve region 5, but is spaced apart from this sleeve region 5 in the radial direction (i.e. in the radial direction with respect to the longitudinal axis a). This creates an area between the sleeve region 5 and the end wall 3 in the form of an annular opening 6, which is open on the front side. That is, the end wall 3 is not held in particular by the sleeve region 5, but only by the support structure 106 (outlined in dashed lines behind the opening 6). The end wall 3 is therefore not connected in particular directly to the front edge 5a of the sleeve region 5.

In the case of a cooling of the base body 4, similar to the conventional embodiment illustrated in fig. 7, a deformation of the front edge 5a of the sleeve region 5 in the direction P1 is no longer possible. Thus, on cooling, the end wall 3 will no longer pull apart (aufziehen) the front edge 5a of the sleeve region 5. Thus, it is much more reliable than hitherto to achieve: the front edge 5a is still in contact with the bearing bushing 108 after the cooling of the basic body 4. Furthermore, a largely symmetrical geometry of the sleeve region 5 occurs in the axial direction (along the longitudinal axis a), which results in a more uniform pressure distribution within the sleeve region 5 when the plastic material cools. This reduces such effects: the sleeve region 5 becomes thinner at the front edge 5a and can therefore lift off the bearing bush 108 or at least reduce the contact pressure.

In order to prevent liquids (e.g. water or lye) and/or gases (e.g. moist air) from possibly escaping uncontrolled from the drum shell 2 via the opening 6, the opening 6 is then covered by means of a cover 7. Since the opening 6 extends here as far as the recess 109 (i.e. the inner edge of the channel-shaped recess 109 merges into the outer edge of the opening 6), the cover 7 has an annular cover region 8 which covers the opening 6 and an annular fan-shaped cover region 9 which adjoins it on the outside for covering the recess 109. This may also be referred to as a cover/lid combination.

The cover 7 can be placed on the front side, for example, onto the base body 4 and then fixedly connected thereto, for example welded (e.g. laser welded), glued, etc. In particular, the cover 7 (since the cover 7 is only subjected to a small mechanical load) is made of inexpensive PP-TV or PP filled with calcium carbonate.

Fig. 3 shows a front view similar to fig. 2 of a rear drum shell section 11 with a cover 15 drawn apart. Instead of the rear drum shell section 103, the rear drum shell section 11 can be, for example, part of a drum shell 12 installed in the domestic washing appliance 101.

The drum shell section 11 differs from the drum shell section 1 in that the drum shell section 11 does not have a cooling channel 111 and therefore neither has a recess 109 in the end wall 13 of the base body 14 nor has a cover region 9 which covers the recess 109. The cover 15 covering the opening 6 can therefore be of simple annular design, for example, similar to the annular region 8 of the drum shell segment 1.

It goes without saying that the invention is not limited to the embodiments shown.

In general, "a" or "an" may be understood as a singular or plural, especially in the sense of "at least one" or "one or more" etc., as long as this is not explicitly excluded, for example by the expression "exactly one" etc.

The numerical designation may also include the stated number in its entirety and include the usual tolerance ranges, as long as this is not explicitly excluded.

List of reference numerals

1 rear drum shell section

2 roller shell

3 end wall

4 base body

5 sleeve area

5a front edge of the sleeve region

6 opening

7 cover part

8 cover region

9 cover part area

11 rear drum shell section

12 roller shell

13 end wall

14 base body

15 cover part

101 household washing appliance

102 drum shell

103 rear drum shell section

104 base body

105 sleeve region

105a front edge of the sleeve region

106 support structure

107 end wall

108 bearing bush

109 retraction part

110 cover member

111 cooling channel

112 opening

113 opening

114 side wall

Longitudinal axis A

L air

P1 Directional arrow (variants)

Claims (9)

1. A drum housing (2; 12) for a domestic washing appliance (101) having a rear drum housing section (1; 11),

wherein the drum shell segment (1; 11) has at least:

-a base body (4; 14) having:

a hollow cylindrical sleeve region (5),

a support structure (106) extending in a radial direction from the sleeve region (5), and

an end wall (3; 13) arranged annularly around the sleeve region (5) and arranged on the front side on the support structure (106), and

a bearing bush (108) which is fixedly surrounded on the outside by the sleeve region (5),

wherein the content of the first and second substances,

-the end wall (3; 13) is spaced apart from the sleeve region (5), and

the open region (6) between the sleeve region (5) and the end wall (3; 13) is covered by a cover (7-9; 15) connected to the end wall (3; 13) and to the sleeve region (5).

2. The drum shell (2) according to claim 1,

-the end wall (3) has a channel-like retraction (109) which is partially covered on the front side by means of a cover (9), and

-the cover (9) is constructed integrally with the cover portion (8).

3. The drum shell (2) according to claim 2,

wherein the channel-like recess (109) is provided as a cooling channel together with the cover (7, 9) for the air (L) escaping from the drum shell (2).

4. The drum shell (2) according to claim 2 or 3,

wherein the inner edge of the channel-like recess (109) transitions into the outer edge of the open region (6).

5. The drum shell (2; 12) according to any of the preceding claims,

wherein the cover element (7-9; 15) is welded to the base body (4, 14).

6. The drum shell (2; 12) according to any of the preceding claims,

wherein the base body (4; 14) is made of a first plastic material, and

the cover portions (7-9; 15) are made of a second plastic material.

7. The drum shell (2; 12) according to any of the preceding claims,

wherein the cover parts (7-9; 15) are made of polypropylene or are made of polypropylene.

8. The drum shell (2; 12) according to any of the preceding claims,

wherein the end wall (3; 13) merges on its outer edge into a forwardly projecting, hollow-cylindrical side wall (114).

9. A domestic washing appliance (101) having a drum shell (2; 12) according to any one of the preceding claims.

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