GB1597880A

GB1597880A - Washing machines

Info

Publication number: GB1597880A
Application number: GB25665/78A
Authority: GB
Original assignee: Societe Internationale de Mecanique Industrielle SA
Current assignee: Societe Internationale de Mecanique Industrielle SA
Priority date: 1977-06-22
Filing date: 1978-05-31
Publication date: 1981-09-16
Also published as: CH625002A5; FR2395347B1; DE2825637B2; IT7824691A0; DE2825637C3; DE2825637A1; IT1096500B; FR2395347A1; ES471039A1

Abstract

The washing machine comprises a tub (11), a cylindrical drum (10) housed inside the tub, driven in a rotational movement by a drive shaft (15) fixed to the centre of one of its end walls, which shaft is supported in rotation by a bearing fixed in a leaktight manner in an opening in the tub. The bearing consists of a cushion (12) made of a frictional material, the end face of the cushion opposite the drum forming the stationary back face of a sealing device. The part of the drive shaft in contact with the cushion is made from a frictional material compatible with that of the cushion, the frictional materials being chosen so as to be water-lubricated. Application to washing machines. <IMAGE>

Description

(54) WASHING MACHINES (71) We, SOCIETE INTERNATIONALE DE MECANIQUE INDUSTRIELLE S.A., a company of Luxembourg of 37 Rue Notre-Dame, Luxembourg, (Grand Duche of Luxembourg), do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement:- This invention relates to a washing machine, in particular a machine for washing linen, comprising a tub, a cylindrical drum, inside the tub, which has a rotary movement imparted to it by a driving shaft fixed centrally of one of its end walls, the shaft being supported for rotation, by a journal, in watertight fashion in an opening in the tub.

The traditional solution for the journal supporting the driving shaft is to use ball bearings. As this ball bearing is greaselubricated, it is essential to avoid any contact between the washing water in the tub and the ball bearing in order to preserve the latter, and also to avoid contamination of the washing water and soiling the linen with grease. For this purpose the ball bearing is protected by a rotary sealing device, of traditional type, of which a rotating part or joint is fixed on the driving shaft inside the tub and a fixed part, or counter ring, of which is fixed to the journal (or vice versa).

A disadvantage of this system is that failure of the sealing device inevitably causes deterioration of the moving part of the ball bearing and therefore necessitates the replacement of the whole bearing. Another disadvantage peculiar to machines for washing linen is that after a large number of washes, the wash water contains fluff of textile material which can penetrate between the faces of the joint and the counter ring in frictional contact with each other and therefore can impair the water-tightness of the joint. Furthermore, the number of parts is considerable, and assembly is a delicate matter.

The invention relates to a washing machine of the above type in which the disadvantages mentioned are eliminated or reduced.

The invention provides a washing machine comprising a tub, a driving shaft mounted for rotation with respect to the tub via a bearing of friction material secured in water-tight manner in an opening in the tub, a cylindrical drum inside the tub having one end wall secured at its centre to the shaft to be driven by the shaft, wherein there is provided a friction sealing ring secured to the shaft via an elastic membrane and resiliently urged into sliding engagement with an end face of the bearing remote from the drum, said end face of the bearing constituting a fixed part of a sealing assembly and said friction sealing ring constituing a rotary part of the sealing assembly.

The washing water cannot damage the journal - on the contrary, it lubricates the bearing and the shaft when they are in contact. Moreover, the washing water which passes between the shaft and the bearing is cleared from the pieces of fluff from the linen and as the sealing assembly is outside the tub, it is only in contact with this "filtered" water and runs less risk of being contaminated. Furthermore, the number of parts is considerably reduced by the fact that the bearing froms itself the counter ring of the sealing device.

The invention is particularly applicable to top loading machines, but it can also be applied to front loading machines.

The invention will be further understood by reading the following description, compiled by referring to the enclosed drawing in which: Fig. 1 shows in an axial cross-section a washing machine in accordance with the invention, of the top loading type; Fig. 2 is a detailed view showing an alternative method of construction; and Fig. 3 is a view similar to Fig. 1 but for a front loading machine.

Fig. 1 shows a top-loading washing machine for washing linen but shows only the parts necessary to the understanding of the invention.

This machine includes a perforated drum having a horizontal axis, of which a central part of end walls 10 is shown. This drum rotates inside a tub, of which walls 11 are shown and which contains washing water.

Of course, the space between the walls 10, that is the width of the drum, has heen considerably reduced compared with actual size.

The two assemblies supporting the drum being largely identical, we shall first of all describe the one shown at the right of the drawing which connects the drum to the drive mechanism.

This journal comprises a bearing 12 fixed in a circular opening of the wall of the tub by a rubber ring 13 which ensures a static watertight sealing, whilst the opening of the wall 11 is provided for this purpose with a pressed-metal projection 14.

A shaft 15 fixed to the wall 10 of the drum is mounted so as to be free to rotate in the bearing 12. This shaft 15 is welded to the wally at its end 16, around which is arranged a bridging washer 17 facilitating the relative axial positioning of the bearing 12 and the shaft 15.

The drive is transmitted to the shaft 15 by a pulley 18, a hub 19 of which is locked to the shaft 15 when it is rotating by virtue of the contact between the mating cones 20 provided on the shaft 15 and the hub 19. A bolt 21 is screwed into a threaded hole 22 formed in the shaft 15 to clamp the hub 19 axially and thus allow the shaft 15 to be driven by the hub 19.

This method of drive is shown only as an example, and any suitable means can be used to ensure that the shaft 15 and hub 19 are connected for rotation together.

The washing water passing between the bearing and the shaft is prevented from escaping from the tub by a sealing assembly, a rotating part of which, or the joint, comprises a friction sealing ring 23 fixed to a membrane 24 of elastomeric material which is supported by the hub 19 and a fixed part of which is formed by an end-face 25 of the bearing 12.

A circlip 26 is provided to secure axially a stop member in the form of a thrust ring 27 supported by the face 25 of the bearing and against a shoulder of the shaft 15, thus ensuring the correct axial positioning of the latter.

It is clear from the above description that the choice of the materials forming the bear ng 12 and the shaft 15 is important. Preferably use should be made for the bearing of a friction material such as moulded or electro-graphited carbon, moulded aluminium or sintered stainless steel. For the shaft 15 stainless steel can be used if the bearing is of carbon and if the loads and spccds are moderate. Otherwise use should be made of stainless steel coated with a material such as aluminium or chormium oxide Cry03 by means of a plasma blowpipe.

The friction sealing ring 23 will consist of a material similar to that of the bearing 12.

The bridging washer 17 and the thrust ring 27 will be of the same material as the shaft 15.

The bearing assembly on the left-hand side of the drawing does not transmit the drive and is therefore simpler. It comprises a pressed-metal cup 30 fixed to the wall 11 of the tub, but does not include any sealing assembly. It does not matter of course if washing water penetrates into the cup 30.

The structure described for the journals presents several advantages compared with traditional ball bearings. The fluff derived from the textile material present in the washing water is stopped by the bearing 12 and cannot damage the rubbing surfaces of the sealing assembly, which is outside the tub. The life of the sealing assembly is therefore definitely longer.

On the other hand, the washing water which passes between the bearing and the shaft lubricates the journal and contributes to the extension of its life.

Moreover the whole of the two journals comprise only one sealing assembly on the drive side, compared with two in the case of ball bearings. Moreover, the space between the side wall 10 of the drum and the respective walls 11 of the tub may be small and certainly much less than as shown on the drawing, which makes it possible to obtain a maximum drum volume for a given tub width, that is, for a specific floor space of the machine.

Finally, each bearing assembly comprises only a small number of parts, and assembly and dismantling are very much simplified.

An advantageous alternative method of construction for the shaft is shown in Fig. 2.

In this case the shaft includes an inside part 40 driven by the hub of the pulley (not shown on this part of the drawing) and a sleeve 41 rigidly fixed to part 40, being adhered, for example, with Loctite (trade mark). Only the sleeve 41 is made from friction material, preferably of carbon or sintered aluminium, the bearing 12 being then for preference of carbon. In the event of a friction arrangement of carbon against carbon, it is preferable to choose a hard quality for the sleeve 41 and a semi-hard quality for the bearing.

Furthermore, the sleeve 41 comprises a collar 42 of large diameter which plays the part of the bridging washer ] 3 shown in Fig.

I.

Let us refer now to Fig. 3 which illustrates the application of the invention to front loading washing machines. In this type of machine the drum is supported in a cantilever arrangement and the driving shaft 55 is supported by two journals arranged side by side.

These journals consist of bearings 52a and 52b respectively, made from friction material, fixed to the tub by means of rubber elements 53a and 53b respectively. The bearing 52a adjacent to the wall 50 of the drum is fixed direct to the wall 51 of the tub, while the bearing 52b, remote from the drum, is fixed to a tubular extension 51b, which is itself welded to the wall 51.

The face of the bearing 52b opposite to the drum constitutes a fixed sliding face of a sealing assembly identical to that of Fig. 1.

As in the case of Fig. 1 this device is adjacent the driving mechanism so that the contact between the bearing 52b and the shaft 55 is lubricated.

For the rest, the description with reference to Fig. 1 remains valid. It should be noted only that the bearings 52a and 52b, have their larger diameter annular flanges at their outer ends.

WHAT WE CLAIM IS: 1. A washing machine comprising a tub, a driving shaft mounted for rotation with respect to the tub via a bearing of friction material secured in watertight manner in an opening in the tub, a cylindrical drum inside the tub having one end wall secured at its centre to the shaft to be driven by the shaft, wherein there is provided a friction sealing ring secured to the shaft via an elastic membrane and resiliently urged into sliding engagement with an end face of the bearing remote from the drum, said end face of the bearing constituting a fixed part of a sealing assembly and said friction sealing ring constituting rotary part of the sealing assembly.

2. A washing machine according to claim 1, wherein the driving shaft is secured to a central hub of a driving member located outside the tub, the elastic membrane being held between the central hub and a stop member secured to the driving shaft.

3. A washing machine according to claim 2, wherein a part of said driving shaft in contact with the bearing has a larger diameter than a part on which the sealing assembly engages and a spacer ring of friction material engages at one end said stop member and at the other end a shoulder joining said two parts of the driving shaft and said end face of the bearing thereby axially to position the shaft with respect to the bearing.

4. A washing machine according to any of claims 1 to 3, wherein the other end wall of the drum is secured to a second shaft rotatable in a second bearing fixed to the tub, said second bearing being identical to said first-mentioned bearing supporting the driving shaft.

5. A washing machine according to claim 4, including a cup-like cover secured to the tub so as to enclose said second shaft and said second bearing.

6. A washing machine according to claim 4, wherein each shaft comprises an inner part and an outer sleeve of friction material surrounding and secured to said inner part.

7. A washing machine according to claim 6, wherein said sleeve flares at the end adjacent the drum wall into a collar acting as a spacer between the respective bearing and the wall of the drum.

8. A washing machine according to any of claims 1 to 3, wherein said bearing is secured to a tubular extension of the tub and a second bearing secured to the tub adjacent said end wall of the drum supports for rotation the driving shaft, said second bearing being identical to the first mentioned bearing.

9. A washing machine according to claim 4 or 8, wherein a spacer washer of friction material is mounted between each bearing adjacent the drum and the end wall of the drum.

10. A washing machine substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. is supported by two journals arranged side by side. These journals consist of bearings 52a and 52b respectively, made from friction material, fixed to the tub by means of rubber elements 53a and 53b respectively. The bearing 52a adjacent to the wall 50 of the drum is fixed direct to the wall 51 of the tub, while the bearing 52b, remote from the drum, is fixed to a tubular extension 51b, which is itself welded to the wall 51. The face of the bearing 52b opposite to the drum constitutes a fixed sliding face of a sealing assembly identical to that of Fig. 1. As in the case of Fig. 1 this device is adjacent the driving mechanism so that the contact between the bearing 52b and the shaft 55 is lubricated. For the rest, the description with reference to Fig. 1 remains valid. It should be noted only that the bearings 52a and 52b, have their larger diameter annular flanges at their outer ends. WHAT WE CLAIM IS:

1. A washing machine comprising a tub, a driving shaft mounted for rotation with respect to the tub via a bearing of friction material secured in watertight manner in an opening in the tub, a cylindrical drum inside the tub having one end wall secured at its centre to the shaft to be driven by the shaft, wherein there is provided a friction sealing ring secured to the shaft via an elastic membrane and resiliently urged into sliding engagement with an end face of the bearing remote from the drum, said end face of the bearing constituting a fixed part of a sealing assembly and said friction sealing ring constituting rotary part of the sealing assembly.