WO2017029416A1

WO2017029416A1 - Drum assembly for a washing machine

Info

Publication number: WO2017029416A1
Application number: PCT/ES2015/070627
Authority: WO
Inventors: Alberto GARCÍA COLLADO; David Ángel MARTÍNEZ LLANOS
Original assignee: Teknia Montmelo, S.L.
Priority date: 2015-08-19
Filing date: 2015-08-19
Publication date: 2017-02-23
Also published as: EP3339491A4; EP3339491A1

Abstract

The invention relates to a drum assembly for a washing machine with a drum and a support assembly for same that is an alternative to an aluminium alloy support and is able to withstand the mechanical forces and chemical attack to which washing machine drums are subjected. The drum assembly comprises a drum and a support assembly that in turn comprises a star-shaped support having at least three arms and a shaft secured at the centre of the support, the star-shaped support comprising a metallic core encapsulated by an overmoulded a plastic covering. For each arm, the metallic core comprises two plates disposed transversely with respect to the main plane of the support assembly, the shaft being secured by the plastic covering.

Description

DRUMMER DRUM ASSEMBLY

TECHNICAL FIELD OF THE INVENTION

The present invention encompasses in the field of washing machines, in particular in the field of their components, such as the drum.

Said invention is a drum assembly for washing machine comprising a drum, a support assembly thereof and fixing means between them.

BACKGROUND OF THE INVENTION

At the moment, in the manufacture of washing machines, for the transmission of the motor rotation movement to the stainless steel drum an aluminum alloy star support with mechanized shaft is attached to it, said fixation is achieved with the same aluminum alloy of the support which overmolds the shaft. This support assembly is subjected to alternating mechanical stresses, due to drum movement, in addition to high temperatures (up to 100 ° C) and chemical attack due to detergents and other

products used for washing clothes. The combination of mechanical stress and chemical attack causes the support set to degrade during the life of the washer, with the subsequent failure and subsequent

Repair or replacement.

Other components of washing machines other than the aforementioned support assembly are known, such as vats with an over-injected metal and plastic core, as in EP2392718. The Cuba does not suffer mechanical stress combined with chemical attacks such as drum support set, so its configuration is simple.

The present invention solves the disadvantages of the state of the art and covers the need for washing machine components that resist mechanical stress and chemical attack.

DESCRIPTION OF THE INVENTION

The present invention is established and characterized in the independent claims, while the dependent claims describe other features thereof.

The object of the invention is a drum assembly for washing machine with drum and support assembly thereof which is an alternative to aluminum alloy and withstands the mechanical stress and chemical attack suffered by washing machine drums. The technical problem to be solved is to configure the components mentioned to achieve the object of the invention.

With star support that includes arms, it is intended to specify that the arms are equidistant from each other, that is, they are divided along the circumference, as in a star with

regular distribution of your arms. The symmetry of such a configuration is implicit in its definition.

In citing overinjection, an implicit characteristic is exposed to plastic encapsulation, as it is the appropriate and known technique for carrying out such a complete wrapping configuration of a element, without wanting to expose a product characteristic by its process of obtaining.

An advantage of the invention in relation to claim 1 is that it more than meets the object of the invention since the arrangement and configuration of the metal core in conjunction with the plastic coating has a greater resistant modulus than the same aluminum alloy assembly, with that better withstand alternating stress and less deformation.

Likewise, the encapsulation avoids any contact of the metal core with the detergents with chlorinated water at high temperature, thereby preventing corrosion unlike in the aluminum alloy of the prior art.

Another advantage in relation to claim 2 is that it adequately resists torsional stresses.

Another advantage in relation to claim 3 is that metal core is used only in the required parts, as verified in the prototypes

tested, which optimizes the location and amount of metal core that is the most expensive and heavy component.

Another advantage in relation to claim 4 is that material is removed from an area where it is not necessary, whereby the cost of the assembly is reduced by using less plastic material and the assembly is also lightened.

Another advantage in relation to claim 5 is that it allows a one-piece metal core to be made for two adjacent arms, making manufacturing easier, usually by stamping a metal plate. Another advantage in relation to claim 6 is that the shaft joint is reinforced with which it better resists the transmission of the torque that it receives and passes to the support assembly. Another advantage according to claim 7 is that it resists torsional stresses on the shaft for any drum condition and load.

Another advantage in relation to claim 8 is that the attachment of the shaft to the metal core is facilitated.

Another advantage in relation to claim 9 is that in addition to the thickness being suitable for

resist the mechanical stresses already mentioned

It provides enough weight to the set to minimize the use of counterweights, compared to the state-of-the-art aluminum alloy that needs counterweights to a greater extent. Another advantage in relation to the claim

10 is that plastics already used in other components of the washing machines are used in the coating and that they can include degrees resistant to the attack of detergents and chlorinated water at high temperature.

Another advantage in relation to the claim

11 is that the fibers are already used in others

components of washing machines and provide great rigidity to the whole. Another advantage in relation to claim 12 is that the fixation is not affected by the relaxation phenomenon and the screws do not need a self-braking additive as occurs in the aluminum alloy of the prior art.

BRIEF DESCRIPTION OF THE FIGURES

The present specification is complemented with a set of figures, illustrative of the preferred example, and never limiting the invention.

Figure 1 represents a rear perspective view of the drum assembly.

Figure 2 represents a section showing in detail the fixing means of a support arm to the drum of the drum assembly of Figure 1. Figures 3A-3C represent a perspective view of the support assembly, of the drum assembly of Figure 1, formed by a star support of 3, 6 and 8 arms respectively. Figure 4 represents a perspective view of an exploded drum assembly of Figure 1.

Figure 5 represents an elevation view of the metal core of the star support.

Figure 6 represents an elevation view of the star support.

Figure 7 represents a cross section of an arm of the star support, related to the section VII of figure 6.

Figure 8 represents a longitudinal section of the support assembly, related to section VIII of Figure 6.

Figure 9 represents a perspective view of the shaft welded to the metal core.

Figure 10 represents a perspective view of the shaft with broaching areas practiced at its end where it joins the metal core.

EXHIBITION OF CARVED PREFERRED EMBODIMENTS OF THE INVENTION

An embodiment of the invention is shown below with support in the figures. Figure 1 shows, as is known in the state of the art, a drum assembly for

washing machine comprising:

-a drum (1) which in turn comprises a cylindrical side wall (1.1) and a rear wall (1.2) covering one of the faces of the cylindrical side wall

(í. D;

-a support assembly (2) which in turn comprises a star support (2.1) with at least three arms (2.1.1) whose ends form the main plane of the support assembly (2), and an axis (2.2) fixed on the center of the support (2.1) and perpendicular to said plane

principal ; - fixing means (3) of each of the arms (2.1.1) of the support (2.1) to the rear part of the drum (1), that is, the part of said drum (1) corresponding to the cylindrical side wall (1.1) covered by the rear wall (1.2).

In the embodiment shown in figures 1, 2 and 4, the arms (2.1.1) of the support (2.1) are fixed to an edge of the cylindrical wall (1.1) protruding from the rear wall (1.2) of the drum (1 ), however, with simple obvious changes, it could be foreseen that the fixation of said arms (2.1.1) is carried out to the rear wall itself (1.2). A preferred embodiment of the star support (2.1) with 3 arms (2.1.1) is shown in Figures 1, 3A and 4, however, they could be used

supports (2.1) with 6 or 8 arms (2.1.1) as the

shown in Figures 3B and 3C respectively.

Figures 4 to 8 show that the star support (2.1) also comprises a metal core (2.1.2) encapsulated by overinjection of a

plastic coating (2.1.3), said metal core (2.1.2) comprises, for each arm (2.1.1), two plates (2.1.4) arranged transversely with respect to the main plane of the support assembly (2), that is, the plates (2.1.4) extend radially in the star support (2.1) with the larger sides of their cross section arranged parallel to the axis (2.2). Each plate (2.1.4) on each arm (2.1.1) has a central part (2.1.5) that hugs a portion of the shaft (2.2) followed by a first section (2.1.6) that extends into each arm ( 2.1.1) up to a second section (2.1.7) as a continuation of the first, the axis (2.2) is fixed by plastic coating (2.1.3).

Normally, the star support (2.1) forms a diameter between a minimum of 300 mm and a maximum of 600 mm. This makes that, next to the fixing means

(3) that are used, compatible with those used in an existing drum assembly, for example by matching threaded holes, makes it possible to replace an existing support assembly (2) with a star support (2.1) in alloy aluminum by one according to the invention.

Optionally, as shown in Figures 4 to 7, on each arm (2.1.1), the second sections (2.1.7) of the plates (2.1.4) are more separated from each other than the first sections (2.1.6 ). Specifically, it is verified that the separation (if) between the first sections (2.1.6) of the plates (2.1.4) can be between 10 and 40 mm, and the separation (s2) between the second sections (2.1.7 ) of the plates (2.1.4) can be between 40 and 200 mm. As shown in Figure 5, the transition between the first (2.1.6) and second tranche (2.1.7) can be done by a smooth transition, that is, rather curved

avoiding shaping vertices, to pass from one

separation to another, although any other configuration is possible.

Another option, as shown in Figure 7, is that the cross section of each arm (2.1.1), corresponding to the first section (2.1.6) of the plates

(2.1.4), it is in U being the plates (2.1.4) with plastic coating (2.1.3) and the central opening (2.1.8) of plastic coating (2.1.3). Figure 8 shows a longitudinal section of an arm (2.1.1), whose profile is inclined, and can have a height between the highest and lowest part of between 20 to 100 rom, although it could also be the straight profile. Small heights are conducive to more compact support sets (2) but with less moment of inertia, more

suitable for drums with less load of clothes, while higher heights are conducive to higher loads of clothes.

Another option, as shown in figures 3, 4, 6 to 8, is that each arm (2.1.1) has a recess

(2.1.9) in at least a portion of the plastic coating (2.1.3) in correspondence with the second section

(2.1.7) of the plates (2.1.4). Another option, as shown in figures 4 and

5, is that the plates are connected continuously

(2.1.4) of two adjacent arms (2.1.1), that is to say, the plates (2.1.4) of two adjacent arms (2.1.1) form the same piece.

Another option, as shown in Figure 9, is that the shaft (2.2) is also fixed to the central part

(2.1.5) of each plate (2.1.4) of each arm (2.1.1) by welding (4), being able to be a cord, as shown, a point, or even a button by filling a hole made in the central part (2.1.5), not shown in the figures.

Another option, as shown in Figure 8, is that the axis (2.2) presents in the portion with

plastic coating (2 1.3) a knurling (2.2.1) with teeth height between 2 and 4 rom.

Another option is that the shaft (2.2) has a broaching (2.2.2) in the central part (2.1.5), that is, in the areas where said central parts (2.1.5) of the plates (2.1.4) are fixed to the axis

(2.2). Figure 10 shows the axis (2.2) with two broaches (2.2.2), however, said axis (2.2) could comprise up to 8 broaches (2.2.2), by

example, depending on the number of arms (2.1.1) that the star support (2.1) possesses.

Another option is that the plates (2.1.4) have a thickness between 1 and 5 rom. In the case of wanting to lighten the weight of the plates (2.1.4) they could be done

holes in them, not shown in the figures.

Another option is that the plastic coating (2.1.3) is reinforced with fibers, the plastic being one selected from PP (polypropylene), PPS

(phenylene polysulfide), PSU (polysulfone) and PET

(polyethylene terephthalate). Whatever the plastic material used, those mentioned or any other, it is advantageous to use the available grades more resistant to chemical attack of detergents, chlorine and high temperature.

Another option is that the fibers are of a material selected from glass, calcium and carbon. The fibers can be short, medium or long, of

preference being between 0.1 and 3 mm in length for glass, and between 1 and 20 μπι for calcium. Another option, as shown in Figure 2, is that the fixing means (3) comprise at least one threaded hole (3.1) in the plastic covering (2.1.3) of each arm (2.1.1) and a screw ( 3.2) with steak angle with self-retention. The options shown do not imply

fulfillment of the option prior to a given one but can be combined with each other in any order and in any way.

Claims

1. -With drum drum for washing machine comprising:

- a drum (1) which in turn comprises a cylindrical side wall (1.1) and a rear wall (1.2) covering one of the faces of the cylindrical side wall (1.1); -a support assembly (2) which in turn comprises a star support (2.1) with at least three arms

(2.1.1) whose ends form the main plane of the support assembly (2), and an axis (2.2) fixed in the center of the support (2.1) and perpendicular to said plane

principal ;

- fixing means (3) of each of the arms

(2.1.1) of the support (2.1) to the rear of the drum (1);

characterized by that

the star support (2.1) also comprises a metal core (2.1.2) encapsulated by overinjection of a plastic coating (2.1.3), said metal core (2.1.2) comprises for each arm (2.1.1) two plates ( 2.1.4) arranged transversely with respect to the main plane of the support assembly (2), each plate (2.1.4) on each arm (2.1.1) has a central part (2.1.5) that hugs a portion of the shaft (2.2) followed by a first section (2.1.6) that extends in each arm

(2.1.1) up to a second section (2.1.7) as a continuation of the first, the axis (2.2) is fixed by the

plastic coating (2.1.3).

2. Set according to claim 1 wherein, in each arm (2.1.1), the second sections (2.1.7) of the plates (2.1.4) are more separated from each other than the first sections (2.1.6 ). 3. - Set according to claims 1 or 2 in the that the cross section of each arm (2.1.1), corresponding to the first section (2.1.6) of the plates (2.1.4), is U, the wings being the plates (2.1.4) with plastic coating (2.1. 3) and the central opening (2.1.8) of plastic coating (2.1.

3) .

4.-Set according to any of the preceding claims in which each arm (2.1.1) has a recess (2.1.9) in at least a portion of the

plastic coating (2.1.3) in correspondence with the second section (2.1.7) of the plates (2.1.4).

5. - Assembly according to any of the preceding claims in which the adjacent two-arm plates (2.1.4) (2.1.1) are continuously connected.

6. Set according to any of the preceding claims wherein the shaft (2.2) is also fixed to the central part (2.1.5) of each plate (2.1.4) of each arm (2.1.1) by welding (4 ).

7. -An assembly according to any of the preceding claims wherein the shaft (2.2) has a knurling (2.2.1) in the portion with plastic coating (2.2.1) with teeth of height between 2 and 4 rom.

8. - Assembly according to any of the preceding claims, wherein the shaft (2.2) has a broaching (2.2.2) in the central part (2.1.5) of the plate (2.1.4).

9. - Assembly according to any of the preceding claims wherein the plates (2.1.4) have a thickness between 1 and 5 rom.

10. - Set according to any of the preceding claims in which the plastic coating (2.1.3) is reinforced with fibers, the plastic one being selected from PP, PPS, PSU and PET.

11. - Set according to claim 10 wherein the fibers are of a material selected from glass, calcium and carbon.

12. -Set according to any of the

The preceding claims in the fixing means (3) comprise at least one threaded hole (3.1) in the plastic covering (2.1.3) of each arm (2.1.1) and a screw (3.2) with fillet angle with

self-retention