Drum housing for household washing appliances and household washing appliances

Abstract

The present 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) at least having: a base body (4) having a hollow cylindrical sleeve region (5), a support structure (106) radially extending from the sleeve region (5), and an end wall (3) annularly surrounding the sleeve region (5) and connected to the support structure (106) on the front side, and a bearing bush (108) fixedly surrounded by the sleeve region (5) on the outside, the end wall (3) being spaced apart from the sleeve region (5), and an open region (6) between the sleeve region (5) and the end wall (3) being covered by a covering part (7-9) connected to the end wall (3) and the sleeve region (5). The domestic washing appliance (101) has such a drum housing (2). The present invention can be advantageously applied especially to washing machines and washer-dryers.

Description

Field of the Invention

[0001] The present invention relates to a drum housing for a domestic washing appliance, the drum housing having a rear / rear drum housing section wherein the drum housing section at least comprises: a base body having a hollow cylindrical sleeve region, a support structure radially extending (abgehend) from the sleeve region, and an end wall annularly arranged around the sleeve region and seated (ansetzen) on the support structure on the front side; a bearing bush (Lagerbuchse) fixedly surrounded by the sleeve region on the outside. The present invention also relates to a domestic washing appliance having such a drum housing. The present invention can be advantageously applied in particular to domestic washing appliances in the form of washing machines and washer-dryers. Background Art

[0002] EP 3 330 428 A1 discloses a drum housing for a domestic washing appliance, which has a rear or rear drum housing section, wherein the drum housing section has: at least one base body made of plastic, the base body having a hollow cylindrical sleeve region at a central portion, a support structure radially extending from the sleeve region, and an end wall annularly arranged around the sleeve region and seated on the support structure on the front side; a bearing bush ( "babbitt") made of metal and fixedly surrounded by the sleeve region on the outside. The bearing bush is for the driving shaft to pass through, and the driving shaft is for rotating the washing drum received in the drum housing. The bearing bush is surrounded by the sleeve region at its edges on the lateral side and on the end side, and is thus fixedly connected to the rear drum housing section. In particular, the end wall is annularly seated on the front-side edge of the sleeve region. In the case of use in a washer-dryer, the rear drum housing section further has an air passage guiding through the base body, and the air passage is laterally delimited by the base body and at least one cover member (Deckel) placed on the base body.

[0003] The manufacture of the rear drum housing section is achieved by an injection molding method, in which the bearing bush is co-extrusion encapsulated or encapsulation-injected with the base body on the outside. For this purpose, the bearing bush can be introduced, for example, into the injection molding die for manufacturing the base body.

[0004] When the base body cools, it is disadvantageous that contact loss may occur between the sleeve region and the bearing bush. Summary of the Invention

[0005] The object of the present invention is to at least partially overcome the disadvantages of the prior art and in particular to provide a possibility that can be simply and inexpensively implemented, to provide a reliable connection between the base body of the rear drum housing section and the bearing bush placed (in particular injected) into the base body.

[0006] This task is solved according to the features of the present invention. Advantageous embodiments are the subject matter of the technical solutions, the description and the drawings of the present invention.

[0007] This task is solved by a drum housing for a domestic washing appliance, the drum housing having a rear drum housing section, wherein the drum housing section at least has:

[0008] - a base body, which has:

[0009] · a hollow cylindrical sleeve region,

[0010] · a support structure extending radially from the sleeve region, and

[0011] · an end wall arranged on the support structure on the front side and arranged annularly around the sleeve region, and

[0012] - a bearing bush fixedly surrounded by the sleeve region on the outside,

[0013] wherein,

[0014] - the end wall is spaced apart from the sleeve region, and

[0015] - the open region between the sleeve region and the end wall is covered by a covering (Abdeckung) connected to the end wall and to the sleeve region.

[0016] Such a drum housing has the advantage that contact losses between the sleeve region and the bearing bush can be avoided. This advantage is based on the recognition that during the cooling of a conventional base body, it is disadvantageous that material shrinkage occurs in the region of the end wall. As a result, the end wall laterally pulls (deforms) the front-side edge of the sleeve region, so that contact losses between the sleeve region and the bearing bush can occur there. By means of the drum housing according to the invention, in the open region between the sleeve region and the end wall (which open region is thus created: the end wall no longer directly transitions to the sleeve region or is no longer arranged on the sleeve region), it is prevented that when the end wall shrinks, the sleeve region warps / deforms (Verzug) in the axial direction. This also prevents, in turn, the plastic on the front edge of the sleeve region from being pulled off (Abziehen) from the bearing bush.

[0017] Another advantage is that now a geometric shape that is largely symmetric in the axial direction (in which axial direction the geometry at both ends of the sleeve is the same) is also created for the sleeve region, which contributes to a more uniform pressure distribution during material cooling. This in turn reduces the effect of thinning of the front-side edge of the sleeve region.

[0018] Since the drum housing is also used to enclose water, lye, and moist air during the laundry treatment process, the open areas are covered by a covering (so as not to impede the above-mentioned function of the drum housing). Since only very small to almost negligible mechanical loads occur, or no mechanical loads occur, in the area of the covering (more precisely, also during operation of the household laundry appliance), a further advantage results: the covering can be made of a particularly inexpensive material, which can be different from the material of the base body.

[0019] The household laundry appliance can be a washing machine or a combined washing / drying appliance ("washer-dryer").

[0020] The drum housing typically receives a rotatable laundry drum in the household laundry appliance. The laundry drum can be rotated by means of a drive shaft guided by a bearing bushing, while the drum housing is arranged non-rotatably (or fixedly) in the household laundry appliance. In particular, the laundry drum can be loaded with laundry on the front side, and such a household laundry appliance is usually referred to as a "front loader". However, the invention is not limited to front loaders, but can also be used, for example, in household laundry appliances equipped with a laundry drum that can be loaded from above (so-called "top loaders").

[0021] For simple placement of the laundry drum, the drum housing is typically constructed in two parts: a drum housing section at the front or on the front side and a rear or rear drum housing section, which are assembled into a unit after the laundry drum has been inserted. Here, the terms "front" or "front side" and "rear" or "rear part" refer to the typical arrangement in a front loader: the front or front side of the front loader faces the user. In the case of use in a top loader, the arrangement at the "front" / "front side" corresponds to the arrangement at the "top", and the arrangement at the "rear" / "rear part" corresponds to the arrangement at the "bottom". In the context of the present description of the invention, even if the invention is not limited thereto, the terms for front loaders are still used.

[0022] The base body determines the basic shape of the rear drum housing section. The base body is made of plastic (in particular a thermoplastic). The base body is in particular an injection-molded part.

[0023] The sleeve region surrounds the outer peripheral surface of the bearing bushing. The sleeve region advantageously extends over the annular end face of the bearing bushing, since this reliably prevents the bearing bushing from slipping out of the sleeve region by form fit. The bearing bushing is fixedly surrounded on the outside by the sleeve region, which includes that the sleeve region and the bearing bushing cannot rotate relative to each other (or are not provided for relative rotation).

[0024] The longitudinal axis of the support structure reference sleeve region extends radially from this sleeve region. The support structure is used to support an end wall arranged on the support structure on the front side (or in front). An advantageous expansion option for a light but stable construction is that the support structure is a ribbed and / or grid-like structure.

[0025] The end walls are arranged around the sleeve region in a circumferentially spaced-apart manner. Such end walls are typically oriented at least approximately vertically. The end walls are spaced apart (radially) from the sleeve region, which in particular includes that the associated open region (or radial gap) is annular.

[0026] An expansion option is that the end wall transitions at its (when viewed from the front side) - typically circular - outer edge to a forwardly projecting hollow cylindrical side wall of the base body. This has the advantage of facilitating the connection to a matching drum housing section on the front side. The base body then has a basin-like or bucket-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 the sleeve region is arranged (especially centrally).

[0027] One configuration is that the end wall has a channel-shaped recess which is partially covered on the front side by a cover part, and this cover part is integrally constructed with the covering part. This achieves the advantage that only one component (i.e., the integral cover part / covering part combination) needs to be installed on the base body. This makes manufacturing, warehousing management, and handling easier. This configuration is particularly advantageous for a washing dryer because process air to be dried can be led out of the drum housing via the air channel.

[0028] One configuration is that the channel-shaped recess together with the covering part is provided as a cooling channel for the air escaping from the drum housing. This has the advantage that a separate condenser can be dispensed with, or a separate condenser can be implemented at least in a smaller size. An expansion option is that the laundry dryer has a heat pump. In the context of current household washing appliances, the air channel can be constructed substantially analogously to EP 3 330 428A1. The cover part can be constructed, for example, in an annular fan shape.

[0029] One configuration is that the inner edge of the channel-shaped recess transitions to the outer edge of the open region. This achieves the advantage that the cover part / covering part combination can be constructed particularly durably (especially without connecting pieces).

[0030] One configuration is that the covering part or (if present) the cover part / covering part combination is welded (e.g., laser welded) to the base body. This achieves a particularly reliable and tight connection. However, this connection can also be made, for example, by bonding, etc.

[0031] In one configuration, the base body is made of a first plastic material and the covering part is made of a second plastic material different therefrom. Advantageously, plastics can be selected specifically such that they are mechanically particularly advantageous and / or particularly inexpensive for a given purpose.

[0032] In one configuration, the covering part has or is made of polypropylene. This material is particularly inexpensive and is mechanically and chemically stable enough for the purpose of covering. An expansion option is that the covering part is made of PP-TV or polypropylene filled with calcium carbonate (CaCO3).

[0033] The task is also solved by a household washing appliance which includes a drum housing having a rear drum housing section as described above. The household washing appliance can be constructed similarly to the above-described drum housing and has the same advantages.

[0034] In particular, the household washing appliance includes a rotatable laundry drum disposed in the drum housing, and the laundry drum can be rotated by means of a drive shaft guided by a bearing bush. Description of the Drawings

[0035] The above-described characteristics, features and advantages of the present invention and the ways and means of how to achieve them become clearer and more clearly understandable in connection with the following schematic description of the embodiments, which are explained in more detail in connection with the drawings. The drawings show:

[0036] Figure 1 A sketch of the rear drum housing section according to the first embodiment is shown in a side view as a sectional view; and

[0037] Figure 2 A sketch of the rear drum housing section according to the first embodiment is shown in a front view;

[0038] Figure 3 A sketch of the rear drum housing section according to the second embodiment is shown in a front view;

[0039] Figure 4 An exploded view of a conventional rear drum housing section for a drum housing of a household washing appliance is shown in an axonometric view;

[0040] Figure 5 A front view showing a conventional rear drum housing section;

[0041] Figure 6 A rear view showing a conventional rear drum housing section; and

[0042] Figure 7A sketch of a conventional rear drum housing section is shown in side view as a sectional view. DETAILED DESCRIPTION

[0043] Figure 4 An exploded view of a conventional rear drum housing section 103 of a drum housing 102 for a domestic washing appliance 101 is shown in perspective view. Figure 5 A front view of a conventional rear drum housing section 103 is shown. Figure 6 A rear view of a conventional rear drum housing section 103 is shown. Figure 7 A simplified sketch of a conventional rear drum housing section 103 is shown in side view as a sectional view. The conventional rear drum housing section 103 is, for example, a simplified embodiment of the rear drum housing section shown in EP 3 330 428 A1 and can be extended analogously to EP 3 330 428 A1 if required.

[0044] The rear drum housing section 103 has a base body 104 made of plastic, the base body 104 having: a hollow cylindrical sleeve region 105; a ribbed support structure 106 extending radially from the sleeve region 105 (see Figure 6 ); an end wall 107 arranged on the support structure 106 on the front side and arranged annularly around the sleeve region 105. The sleeve region 105 surrounds the outer side of a metal bearing bush 108 having a longitudinal axis A.

[0045] The end wall 107 has an annular sector-shaped channel-like recess 109, which is partially covered on the front side by a mating annular sector-shaped cover 110. The recess 109 and the cover 110 form a channel (in particular a cooling channel 111) for air L escaping from the drum housing 102. For this purpose, the cover 110 does not completely cover this channel-like recess 109, but leaves an opening 112 through which air L can enter the cooling channel 111 and can exit again via a corresponding opening 113 in the end wall 107.

[0046] Furthermore, the end wall 107 transitions at its radially outer edge to a forwardly projecting, hollow cylindrical side wall 114 of the base body 104.

[0047] As shown in Figure 7 , during the cooling of the conventional base body 104 during the injection molding process, due to the asymmetrical attachment to the sleeve end, an uneven pressure distribution is generated in the axial or longitudinal direction of the sleeve region 105. In addition, due to the attachment of the end wall 107 to the front edge 105a of the sleeve region 105, the pulling down of the plastic from the bearing bush 108 is achieved by deformation in the direction P1 (deformation caused by the attachment of the end wall 107).

[0048] Figure 1 A sketch of the rear drum housing section 1 according to the first embodiment is shown in side view as a sectional view. Figure 2 A sketch of the rear drum housing section 1 with the cover part 7 drawn in separately is shown in front view. Instead of the rear drum housing section 103, the rear drum housing section 1 can, for example, be part of the drum housing 2 installed in a domestic washing appliance 101.

[0049] The drum housing section 1 differs from the drum housing section 103 in that the end wall 3 of the base body 4 no longer transitions to the sleeve region 5, but is spaced apart from this sleeve region 5 in the radial direction (that is, radially with respect to the longitudinal axis A). As a result, an area that is open at the front side and has the form of an annular opening 6 is created between the sleeve region 5 and the end wall 3. That is to say, the end wall 3 is not held by the sleeve region 5 in particular, but only by the support structure 106 (outlined in dashed lines behind the opening 6). Thus, the end wall 3 is not directly connected to the front edge 5a of the sleeve region 5 in particular.

[0050] In the case where the base body 4 is cooled analogously to the conventional embodiment described in Figure 7 , a deformation of the front edge 5a of the sleeve region 5 in the direction P1 is no longer possible. Thus, during cooling, the end wall 3 will no longer pull up the front edge 5a of the sleeve region 5. Thus, it is achieved much more reliably than hitherto that the front edge 5a still contacts the bearing bush 108 after the base body 4 has cooled. In addition, a largely symmetrical geometry of the sleeve region 5 occurs in the axial direction (along the longitudinal axis A) here, which contributes to a more uniform pressure distribution inside the sleeve region 5 when the plastic material cools. This reduces the effect that the sleeve region 5 becomes thinner at the front edge 5a and may thus lift off from the bearing bush 108 or at least may reduce the pressing pressure.

[0051] In order to prevent liquid (such as water or lye) and / or gas (such as moist air) from possibly escaping uncontrollably from the drum housing 2 via the opening 6, the opening 6 is then covered by means of the cover part 7. Since the opening 6 extends to the retraction part 109 here (that is: the inner edge of the channel-shaped retraction part 109 transitions to the outer edge of the opening 6), the cover part 7 has an annular cover part region 8 that covers the opening 6 and a ring-shaped fan-shaped cover part region 9 that is adjacent to it on the outside and covers the retraction part 109. This can also be referred to as a cover part / cover combination.

[0052] The covering part 7 can be placed, for example, on the front side onto the base body 4 and then fixedly connected thereto, for example by welding (e.g., laser welding), gluing, etc. In particular, the covering part 7 (since this covering part 7 is only subjected to very little mechanical stress) is made of inexpensive PP-TV or PP filled with calcium carbonate.

[0053] Figure 3 In a front view similar to Figure 2 a sketch of the rear drum housing section 11 with the separately drawn-in covering part 15 is shown. Instead of the rear drum housing section 103, the rear drum housing section 11 can, for example, be part of a drum housing 12 installed in a domestic washing appliance 101.

[0054] The drum housing section 11 differs from the drum housing section 1 in that the drum housing section 11 does not have a cooling channel 111 and thus neither has a recess 109 in the end wall 13 of the base body 14 nor a cover part area 9 covering the recess 109. Accordingly, the covering part 15 covering the opening 6 can be constructed in a simple ring shape, for example, similar to the ring-shaped area 8 of the drum housing section 1.

[0055] It goes without saying that the invention is not limited to the embodiments shown.

[0056] In general, "one" can be understood as singular or plural, in particular in the sense of "at least one" or "one or more", etc., can be understood as singular or plural, as long as this is not explicitly excluded, for example, by an expression such as "exactly one", etc.

[0057] Numeric specifications can also exactly include the specified number and include the usual tolerance ranges, as long as this is not explicitly excluded.

[0058] List of reference numerals

[0059] 1 Rear drum housing section

[0060] 2 Drum housing

[0061] 3 End wall

[0062] 4 Base body

[0063] 5 Sleeve area

[0064] 5a Front edge of the sleeve area

[0065] 6 Opening

[0066] 7 Covering part

[0067] 8 Covering part area

[0068] 9 Cover part area

[0069] 11 Rear drum housing section

[0070] 12 Drum housing

[0071] 13 End wall

[0072] 14 Substrate

[0073] 15 Cover

[0074] 101 Household washing appliance

[0075] 102 Drum housing

[0076] 103 Rear drum housing section

[0077] 104 Substrate

[0078] 105 Sleeve area

[0079] 105a Front edge of the sleeve area

[0080] 106 Support structure

[0081] 107 End wall

[0082] 108 Bearing bush

[0083] 109 Retraction part

[0084] 110 Cover part

[0085] 111 Cooling channel

[0086] 112 Opening

[0087] 113 Opening

[0088] 114 Side wall

[0089] A Longitudinal axis

[0090] L Air

[0091] P1 Direction arrow (variant)

Claims

1. A drum housing (2; 12) for a domestic washing appliance (101), the drum housing having a rear drum housing section (1; 11), Among them, The drum housing section (1; 11) has at least: - A base body (4; 14), the base body having: · A hollow cylindrical sleeve region (5), · A support structure (106) extending radially from the sleeve region (5), and · An end wall (3; 13) arranged on the support structure (106) on the front side and arranged annularly around the sleeve region (5), and - A bearing bush (108) fixedly surrounded by the sleeve region (5) on the outside, wherein, - The end wall (3; 13) is spaced apart from the sleeve region (5), and - The open region between the sleeve region (5) and the end wall (3; 13) is covered by a covering part connected to the end wall (3; 13) and to the sleeve region (5).

2. The drum housing (2) according to claim 1, wherein, - The end wall (3) has a channel-shaped recess (109), the channel-shaped recess being partially covered on the front side by a cover piece, and - The cover piece is integrally formed with the covering part.

3. The drum housing (2) according to claim 2, Among them, The channel-shaped recess (109) and the covering part are jointly provided as a cooling channel for air (L) escaping from the drum housing (2).

4. The drum housing (2) according to claim 2 or 3, Among them, The inner edge of the channel-shaped recess (109) transitions to the outer edge of the open region.

5. The drum housing (2; 12) according to any one of claims 1-3, Among them, The covering part is welded to the base body (4, 14).

6. The drum housing (2; 12) according to any one of claims 1-3, Among them, The base body (4; 14) is made of a first plastic material, and The covering part is made of a second plastic material.

7. The drum housing (2; 12) according to any one of claims 1-3, Among them, The covering part has or is made of polypropylene.

8. The drum housing (2; 12) according to any one of claims 1-3, Among them, The end wall (3; 13) transitions at its outer edge to a forwardly projecting, hollow cylindrical side wall (114).

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

Images