DE102020207452A1 - Drum housing for household washing machine and household washing machine - Google Patents

Abstract

A drum housing (2) is provided for a household washing appliance (101) with a rear drum housing section (1), the drum housing section (1) having at least: a base body (4) with a hollow cylindrical sleeve area (5), one of the sleeve area ( 5) radially outgoing support structure (106) and an end wall (3) arranged in a ring around the sleeve area (5) and attached to the front of the support structure (106) and a bearing bush (108) firmly surrounded on the outside by the sleeve area (5), the end wall (3) is spaced from the sleeve area (5) and an open area (6) between the sleeve area (5) and the end wall (3) by a cover (7-9) connected to the end wall (3) and the sleeve area (5) ) is covered. A household washing appliance (101) has such a drum housing (2). The invention is particularly advantageously applicable to washing machines and washer-dryers.

Description

The invention relates to a drum housing for a domestic washing appliance with a rear drum housing section, the drum housing section having at least: a base body with a hollow cylindrical sleeve area, a support structure extending radially from the sleeve area and an end wall arranged in a ring around the sleeve area and attached to the front of the support structure a bearing bush firmly surrounded on the outside by the sleeve area. The invention also relates to a household washing machine with such a drum housing. The invention is particularly advantageously applicable to household washing appliances in the form of washing machines and washer-dryers.

EP 3 330 428 A1 discloses a drum housing for a household washing appliance with a rear or rear drum housing section, the drum housing section having at least one base body made of plastic with a hollow cylindrical sleeve area located in the center, a support structure extending radially from the sleeve area and a support structure attached to the front of the support structure, ring-shaped around the Has an end wall arranged in the sleeve area and a metal bearing bushing that is firmly surrounded on the outside by the sleeve area. The bearing bushing serves to lead through a drive shaft for rotating a laundry drum to be received in the drum housing. The bearing bush is surrounded by the sleeve area on the side and on its front edges and is thus firmly connected to the rear drum housing section. In particular, the end wall starts in the form of a ring on a front edge of the sleeve area. When used in the washer-dryer, the rear drum housing section also has an air duct leading through the base body, which is laterally delimited by the base body and at least one cover placed on the base body.

The rear drum housing section is produced by means of an injection molding process in which the base body is overmolded or cast around the bearing bush on the outside. For this purpose, the bearing bush can e.g. be inserted into an injection molding tool to manufacture the base body.

When the base body cools, it can disadvantageously lead to a loss of contact between the sleeve area and the bearing bush.

It is the object of the present invention to at least partially overcome the disadvantages of the prior art and, in particular, to provide a simple and inexpensive way to implement a reliable connection between a base body of a rear drum housing section and a bearing bush introduced therein, in particular cast.

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 drawings.

• - einen Basiskörper mit einem hohlzylindrischen Hülsenbereich, einer von dem Hülsenbereich radial abgehenden Stützstruktur und einer frontseitig an der Stützstruktur ansetzenden, ringförmig um den Hülsenbereich angeordneten Stirnwand und
• - eine von dem Hülsenbereich außenseitig fest umgebene Lagerbuchse,

wobei

• - die Stirnwand von dem Hülsenbereich beabstandet ist und
• - ein offener Bereich zwischen dem Hülsenbereich und der Stirnwand durch eine mit der Stirnwand und dem Hülsenbereich verbundene Abdeckung abgedeckt ist.

The object is achieved by a drum housing for a household washing appliance with a rear drum housing section, the drum housing section having at least:

• a base body with a hollow cylindrical sleeve area, a support structure extending radially from the sleeve area and an end wall which is attached to the front of the support structure and is arranged in a ring around the sleeve area and
• - a bearing bush firmly surrounded on the outside by the sleeve area,

whereby

• - The end wall is spaced from the sleeve area and
• an open area between the sleeve area and the end wall is covered by a cover connected to the end wall and the sleeve area.

This drum housing has the advantage that the loss of contact between the sleeve area and the bearing bush can be avoided. This advantage is based on the knowledge that when the conventional base body cools, there is disadvantageous material shrinkage in the area of the end wall. As a result, the end wall pulls the front edge of the sleeve area laterally (warpage) so that there can be a loss of contact between the sleeve area and the bearing bush. Due to the open area of the drum housing according to the invention between the sleeve area and the end wall, which results from the fact that the end wall no longer merges directly into the sleeve area or is no longer attached to the sleeve area, the warping of the sleeve area in the axial direction is reduced when the Front wall prevented. This in turn also prevents the plastic at the front edge of the sleeve area from being pulled off the bearing bush.

Another advantage is that there is now a largely symmetrical geometry of the sleeve area in the axial direction (with the same geometry at both sleeve ends), which leads to a more homogeneous pressure distribution when the material cools. This in turn reduces the effect that the front edge of the sleeve area becomes thinner.

Since the drum housing is used, among other things, to house water, lye and moist air during a laundry treatment process, the open area is covered by the cover in order not to impair this function of the drum housing. Because there is little to practically negligible mechanical stress in the area of this cover, even during operation of the household washing appliance, there is the further advantage that the cover can be made from a particularly inexpensive material that differs from the material of the base body can.

The household washing device can be a washing machine or a combined washing / drying device (“washer-dryer”).

The drum housing typically accommodates a rotatable laundry drum in the household washing appliance. While the laundry drum is rotatable by means of the drive shaft guided through the bearing bushing, the drum housing is not rotatable or is arranged in a stationary manner in the household washing appliance. In particular, the laundry drum can be loaded with laundry from the front, the household washing appliance then often being referred to as a “front loader”. However, the present invention is not limited to front loaders, but can also be used, for example, in household washing appliances (so-called "top loaders") equipped with laundry drums that can be loaded from above.

For easy accommodation of the laundry drum, the drum housing is typically designed in two parts with a front or front drum housing section and a rear or rear drum housing section, which are assembled after the laundry drum has been used. The terms “front” or “front” and “rear” or “rear” refer to the typical arrangement in a front loader, the front or front of which faces a user. When used in a top loader, an arrangement corresponds to “front” “/“ Front ”of an arrangement“ above ”and an arrangement“ rear ”/“ rear ”of an arrangement“ below. ”In the context of the present description of the invention, the terms for a front loader are used throughout, even if the invention is not restricted to them .

The base body determines the basic shape of the rear drum housing section. It consists of plastic, in particular thermoplastic plastic. The base body is in particular an injection molded component.

The sleeve area surrounds the outer surface of the bearing bush. It advantageously extends over the annular end faces of the bearing bush, since in this way a form fit reliably prevents the bearing bush from being able to slip out of the sleeve area. The fact that the bearing bush is firmly surrounded on the outside by the sleeve area means that the sleeve area and the bearing bush are not rotatable relative to one another or are not provided for mutual rotation.

The support structure extends radially therefrom with respect to the longitudinal axis of the sleeve area. It serves to support the front wall arranged thereon. It is an advantageous further development for a light but stable construction that the support structure is a rib-like and / or lattice-like structure.

The end wall is arranged around the sleeve area in a ring-shaped manner. The end wall is typically oriented at least approximately vertically. The fact that the end wall is at a distance (radially) from the sleeve area includes, in particular, that the associated open area or the radial gap is annular.

It is a further development that the end wall merges at its (when viewed from the front) - typically circular - outer edge into a forwardly protruding, hollow cylindrical side wall of the base body. This results in the advantage that a connection with a matching front drum housing section is made easier. The base body then has a tub-like or tub-like basic shape. This can also be expressed in such a way that the base body then has a hollow-cylindrical basic shape with an end face in which the sleeve area is arranged, in particular in the center.

It is an embodiment that the end wall has a channel-shaped recess which is partially covered on the front side by means of a cover and the cover is formed in one piece with the cover. This has the advantage that only one component, namely the one-piece lid / cover combination, needs to be attached to the base body. This facilitates production, storage and handling. This configuration is particularly advantageous for washer-dryers, since process air to be dried can be discharged from the drum housing through the air duct.

It is an embodiment that the channel-shaped recess is set up together with the cover as a cooling channel for air escaping from the drum housing. This results in the advantage that a separate capacitor can be dispensed with or the separate capacitor can at least be made smaller. It is a further development that the washer-dryer has a heat pump. In the context of the present household washing appliance, the air duct can in principle be analogous to EP 3 330 428 A1 be trained. For example, the cover can be designed in the shape of a sector of a ring.

It is an embodiment that an inner edge of the channel-shaped recess merges into an outer edge of the open area. This has the advantage that the lid / cover combination can be designed to be particularly robust, especially without webs.

It is an embodiment that the cover or - if present - the cover / cover combination is welded to the base body, e.g. laser welded. This enables a particularly reliable and tight connection. The connection can also be made, for example, by gluing, etc.

It is an embodiment that the base body consists of a first plastic material and the cover consists of a different second plastic material. In this way, plastics can advantageously be specifically selected which are mechanically particularly advantageous and / or particularly inexpensive for the given purpose.

It is an embodiment that the cover comprises polypropylene or consists of polypropylene. This material is particularly inexpensive and sufficiently mechanically and chemically stable for the purpose of covering. It is a further development that the cover consists of PP-TV or of calcium carbonate (CaC03) -filled polypropylene.

The object is also achieved by a household washing appliance which has a drum housing with a rear drum housing section as described above. The household washing appliance can be designed analogously to the drum housing and has the same advantages.

In particular, the household washing appliance has a rotatable laundry drum which is accommodated in the drum housing and which is rotatable by means of a drive shaft guided through the bearing bush.

• 1 zeigt als Schnittdarstellung in Seitenansicht eine Skizze des eines rückwärtigen Trommelgehäuseabschnitts gemäß einem ersten Ausführungsbeispiel; und
• 2 zeigt in Frontansicht eine Skizze des rückwärtigen Trommelgehäuseabschnitts gemäß dem ersten Ausführungsbeispiel;
• 3 zeigt in Frontansicht eine Skizze eines rückwärtigen Trommelgehäuseabschnitts gemäß einem zweiten Ausführungsbeispiel;
• 4 zeigt in Schrägansicht eine Explosionsdarstellung eines herkömmlichen rückwärtigen Trommelgehäuseabschnitts eines Trommelgehäuses für ein Haushalts-Waschgerät;
• 5 zeigt eine Frontansicht des herkömmlichen rückwärtigen Trommelgehäuseabschnitts;
• 6 zeigt eine Rückansicht des herkömmlichen rückwärtigen Trommelgehäuseabschnitts; und
• 7 zeigt als Schnittdarstellung in Seitenansicht eine Skizze des herkömmlichen rückwärtigen Trommelgehäuseabschnitts.

The properties, features and advantages of this invention described above and the manner in which they are achieved will become clearer and more clearly understood in connection with the following schematic description of an exemplary embodiment which is explained in more detail in connection with the drawings.

• 1 shows, as a sectional illustration in side view, a sketch of a rear drum housing section according to a first embodiment; and
• 2 shows a front view of a sketch of the rear drum housing section according to the first embodiment;
• 3 shows a front view of a sketch of a rear drum housing section according to a second embodiment;
• 4th shows an exploded perspective view of a conventional rear drum housing section of a drum housing for a domestic washing appliance;
• 5 Fig. 13 is a front view of the conventional rear drum shell section;
• 6th Fig. 13 is a rear view of the conventional rear drum shell section; and
• 7th FIG. 11 shows a sectional side view of a sketch of the conventional rear drum housing section.

4th Figure 12 shows an exploded perspective view of a conventional rear drum housing section 103 a drum housing 102 for a household washing machine 101 . 5 Fig. 13 is a front view of the conventional rear drum shell section 103 . 6th Fig. 13 is a rear view of the conventional rear drum shell section 103 . 7th shows, as a sectional illustration in side view, a simplified sketch of the conventional rear drum housing section 103 . The conventional rear drum shell section 103 represents a simplified version of the in EP 3 330 428 A1 shown rear drum housing section and can if necessary analogous to EP 3 330 428 A1 be trained.

The rear drum housing section 103 has a base body 104 made of plastic with a hollow cylindrical sleeve area 105 , one of the sleeve area 105 radially extending rib-like support structure 106 (please refer 6th ) and one on the front of the support structure 106 attached, ring-shaped around the sleeve area 105 arranged front wall 107 on. The sleeve area 105 surrounds an outside of a metallic bearing bush 108 with longitudinal axis A. .

The front wall 107 has an annular sector-shaped channel-shaped recess 109 on, by means of a matching ring sector-shaped cover 110 is partially covered on the front. The return 109 and the lid 110 form a channel, in particular a cooling channel 111 , for out of the drum housing 102 escaping air L. . The lid covers this 110 the channel-shaped recess 109 not completely, but an opening remains 112 through which the air L. in the cooling duct 111 can enter and through a corresponding opening 113 in the front wall 107 can exit again.

The front wall also goes 107 at its radial outer edge in a forwardly projecting, hollow cylindrical side wall 114 of the base body 104 over.

As in 7th indicated, results when the conventional base body cools down 104 an inhomogeneous pressure distribution in the axial or longitudinal direction of the sleeve area during an injection molding process 105 due to the asymmetrical connections at the sleeve ends. By connecting the front wall 107 to the front edge 105a of the sleeve area 105a the plastic is also pulled off the bearing bush 108 by default towards P1 (by connecting the front wall 107 caused delay).

1 shows as a sectional illustration in side view a sketch of a rear drum housing section 1 according to a first embodiment. 2 shows a front view of a sketch of the rear drum housing section 1 with separately drawn cover 7th . The rear drum housing section 1 can, for example, instead of the rear drum housing section 103 as part of a drum housing 2 in the household washing machine 101 be built in.

The drum housing section 1 differs from the drum housing section 103 in that the front wall 3 of the base body 4th now no longer in the sleeve area 5 merges, but in the radial direction (ie, radial to the longitudinal axis A. ) is spaced from this. This creates an area that is open at the front in the form of an annular opening 6th between the sleeve area 5 and the front wall 3 . The front wall 3 is therefore in particular not through the sleeve area 5 held, but only through the (dotted behind the opening 6th indicated) support structure 106 . The front wall 3 consequently, in particular, it is not directly connected to a leading edge 5a of the sleeve area 5 connected.

When the base body cools down 4th analogous to the in 7th described conventional design can warp the front edge 5a of the sleeve area 5 in the direction P1 no longer occur. The front wall 3 becomes the front edge when it cools down 5a of the sleeve area 5 no longer wind up. This achieves the front edge much more reliably than before 5a the bearing bush 108 even after the base body has cooled down 4th contacted. In addition, a largely symmetrical geometry of the sleeve area now results 5 in the axial direction (along the longitudinal axis A. ), resulting in a more homogeneous pressure distribution within the sleeve area 5 when the plastic material cools down. This reduces the effect that the sleeve area is at the front edge 5a becomes thinner and can therefore also stand out from the bearing bush or at least a contact pressure can be reduced.

To prevent liquid (e.g. water or lye) and / or gas (e.g. moist air) from flowing through the opening in an uncontrolled manner 6th from the drum housing 2 can escape is the opening 6th by means of a cover 7th covered. As the opening 6th here up to the return 109 extends (an inner edge of the channel-shaped recess 109 so in an outer edge of the opening 6th passes), the cover points 7th one the opening 6th covering annular coverage area 8th and an annular sector-shaped cover area adjoining it on the outside 9 to cover the recess 109 on. This can also be referred to as a cover / lid combination.

The cover 7th can, for example, be placed on the front of the base body 4th placed on and then firmly connected to this, e.g. welded (e.g. laser welded), glued, etc. In particular, the cover 7th As they are only exposed to low mechanical loads, they are made of inexpensive PP-TV or PP filled with calcium carbonate.

3 shows in to 2 analog front view shows a sketch of a rear drum housing section 11 with separately drawn cover 15th . The rear drum housing section 11 can, for example, instead of the rear drum housing section 103 as part of a drum housing 12th in the household washing machine 101 be built in.

The drum housing section 11 differs from the drum housing section 1 by not having a cooling duct 111 and thus neither a recess in the front wall 13th of the base body 14th one more jump back 109 covering lid area 9 having. The opening 6th covering cover 15th can therefore simply be designed to be ring-shaped, for example analogous to the ring-shaped area 8th of the drum housing section 1 .

It goes without saying that the present invention is not restricted to the exemplary embodiment shown.

In general, “a”, “one” etc. can be understood as a singular or plural number, in particular 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 a "etc.

A number can also include exactly the specified number as well as a customary tolerance range, as long as this is not explicitly excluded.

List of reference symbols

1

Rear drum housing section

2

Drum housing

3

Front wall

4th

Base body

5

Sleeve area

5a

Front edge of the sleeve area

6th

opening

7th

cover

8th

Coverage area

9

Lid area

11th

Rear drum housing section

12th

Drum housing

13th

Front wall

14th

Base body

15th

cover

101

Household washing machine

102

Drum housing

103

Rear drum housing section

104

Base body

105

Sleeve area

105a

Front edge of the sleeve area

106

Support structure

107

Front wall

108

Bearing bush

109

Return

110

lid

111

Cooling duct

112

opening

113

opening

114

Side wall

A.

Longitudinal axis

L.

air

P1

Direction arrow (delay)

QUOTES INCLUDED IN THE DESCRIPTION

This list of the documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent literature cited

• EP 3330428 A1 [0002, 0020, 0028]

Claims (9)

Drum housing (2; 12) for a domestic washing appliance (101) with a rear drum housing section (1; 11), the drum housing section (1; 11) having at least: - A base body (4; 14) with a hollow cylindrical sleeve area (5), a support structure (106) extending radially from the sleeve area (5) and an end wall (106) attached to the front of the support structure (106) and arranged in a ring around the sleeve area (5) ( 3; 13) and - A bearing bush (108) firmly surrounded on the outside by the sleeve area (5), wherein - The end wall (3; 13) is spaced from the sleeve area (5) and - An open area (6) between the sleeve area (5) and the end wall (3; 13) is covered by a cover (7-9; 15) connected to the end wall (3; 13) and the sleeve area (5). Drum housing (2) Claim 1 wherein - the end wall (3) has a channel-shaped recess (109) which is partially covered at the front by means of a cover (9) and - the cover (9) is formed in one piece with the cover (8). Drum housing (2) Claim 2 , wherein the channel-shaped recess (109) is set up together with the cover (7, 9) as a cooling channel for air (L) escaping from the drum housing (2). Drum housing (2) according to one of the Claims 2 or 3 , wherein an inner edge of the channel-shaped recess (109) merges into an outer edge of the open area (6). Drum housing (2; 12) according to one of the preceding claims, wherein the cover (7-9; 15) is welded to the base body (4; 14). Drum housing (2; 12) according to one of the preceding claims, wherein the base body (4; 14) consists of a first plastic material and the cover (7-9; 15) consists of a second plastic material. Drum housing (2; 12) according to one of the preceding claims, wherein the cover (7-9; 15) comprises polypropylene or consists of polypropylene. Drum housing (2; 12) according to one of the preceding claims, wherein the end wall (3; 13) merges at its outer edge into a forwardly projecting, hollow cylindrical side wall (114). Domestic washing appliance (101) having a drum housing (2; 12) according to one of the preceding claims.

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