GB2086946A - Laundry washing machine having a horizontal drum mounted in two bearings arranged in movable supports - Google Patents

Abstract

A washing machine has a horizontal drum 4 whose two shafts 5 are mounted in removable bearing supports 20, 30 arranged in the wall of the tub 1. The first support 20 is latched to the tub wall, whilst the second support 30 has the form of a bushing 31 with a shoulder 34 which is slid into a cylindrical recess 32 in the tub wall. The shoulder 34 is urged against the interior of the tub wall by the elastic force as a result of an axial Compression of the drum 4 between the two bearing supports. The support 20 is held in its bore by a bayonet coupling 26 and has a recess 27 which is out of centre so that the angular position of the support can be adjusted to adjust tension of a drive belt (11), Fig. 1 (not shown), inside the tub. <IMAGE>

Description

SPECIFICATION Laundry washing machine having a horizontal drum mounted in two bearings arranged in movable supports The invention relates to a laundry washing machine comprising a tub for receiving the washing or rinsing water, inside which a laundry drum having a substantially horizontal axis can rotate, which drum is supported by two shafts, whose bearings are mounted in two respective removable bearing supports arranged in the tub wall. Such machines are known. The ease of removal of said bearings in order to replace them depends on the drum-bearing supports. For example, French Patent Specification No. 1,352,933 describes bearing supports which are screwed into the tub wall and which can be removed via the interior of the drum.

It is an object of the invention to simplify the mounting and removal of said bearings and to reduce the number of parts to be assembled for mounting the bearings on the drum and the tub. In particular, this makes it possible to reduce the number of separate spare parts to be stocked for maintenance and repair of washing machines.

Furthermore, the invention makes it possible to carry out ail service operations to the drum bearings from one side of the drum, requiring only one side of the housing to be removed.

To this end a washing machine according to the invention is characterized in that a first of the two bearing supports is axially retained on the tub wall, whilst the second bearing support has the form of a bushing with a shoulder, which bushing is slid into a cylindrical recess in the tub wall until said shoulder butts against the inner side of said wall, said second bearing support being retained under the influence of the elastic force produced by an axial compression of the washing drum. In a washing machine of the conventional type, the tub comprises a substantially cylindrical receptable having a horizontal axis, the back plate and the removable cover constituting the vertical side plates in whose centres the bearings are mounted.

In such a machine the first bearing support may be situated on the removable cover and the second bearing support in the back plate. The second bearing support can then be mounted or removed from inside the tub, after the cover of said tub as well as the washing drum have been removed.

In particular, in the case of a tub construction as described in the foregoing, it is desirable that the side plate of the tub constituting the cover can be mounted or removed while the drum is not secured to it. Therefore, the first bearing support preferably has the shape of a bushing with an external shoulder, which bushing is slid into a cylindrical recess in the tub wall until said shoulder butts against the order side of said wall.

The two bearing supports are then arranged so that they ca be slid into the corresponding recess in the tub wall from the same direction. The first bearing support may be axially retained on the tub wall by means of screws or by a bayonet coupling.

Since the second bearing support is only pressed against the tub wall by the drum, it is important that the sealing between said support and the tub does not depend on said pressure.

Therefore, static sealing between the bearing supports and the tub wall is provided by an O-ring which is disposed in a hollow peripheral groove in the cylindrical surface of the bearing support and which is compressed by the cylindrical surface of the recess receiving said support.

In a special embodiment each bearing support is made of a moulded synthetic material and, for receiving the bearing, comprises an axial cylindrical recess which is open towards the outside of the tub, whose back and inner periphery are grooved and whose opening is restricted by a projection behind which the bearing is fitted by force, the back of said recess constituting a partition which, at the inside the tub, engages with the lip of a rotary seal, mounted on eadh shaft. Thus, the bearing is exposed to the air and any leakage water or condensation formed outside the rotary seal is thus drained and removed by evaporation, without the risk of corrosion for the bearing.

For an extremely simple mounting and removal of a bearing, it is advantageous to combine the bearing support, the bearing and the drum shaft to an assembly which is ready for installation. For this purpose each shaft is fixed to its bearing and is coupled to the drum by means of a flange which is secured to the centre of each side plate of the drum, the corresponding shaft and flange being aligned by abutment of co-operating conical surfaces. The pressure of the side plates of the clamped-in drum, suffices to maintain the flanges and shafts assembled. It may be preferable to secure each shaft to its flange by means of a bolt which passes axially through the shaft and which is screwed into the flange.

An embodiment of a washing machine in accordance with the invention will be described with reference to the drawings.

Figure 1 is a general, partly cut-away, view of a washing machine.

Figure 2 is a sectional view of the bearing areas taken on the axis of the washing drum.

Figure 1 schematically represents a laundry washing and drying machine in accordance with the invention, in which machine the tub 1 for receiving or rinsing water is supported by two spring damping members 2 relative to an outer housing 3 and to its base. The tub 1 accommodates a washing drum 4 made of perforated stainless steel sheet and supported by its shafts 5, which define a substantially horizontal axis of rotation for the drum. The tub is open at its top and the drum shell (cylindrical surface) comprises a door for loading and unloading the laundry to be washed. The electric motor 7 for rotating the drum 4, is mounted on the outside of the tube near its lower part, the shaft of said motor penetrating directly into a housing which forms part of the tub.Inside the tub the motor shaft carries a motor pulley which receives a belt 11 which is tensioned on the cylindrical surface of the washing drum.

The tub 1 can be made of an injection-moulded synthetic material, for example of polypropylene which may be fibre-reinforced, and may comprise a substantially cylindrical main body 14, with a back, closed by a cover 15. The body and the cover are interconnected by elastic straps 16 and between them a seal is clamped.

The selected example concerns a washing machine whose drum is driven by a belt inside the tub. The invention also applies to a machine with a belt, arranged on a driven pulley mounted on one of the shafts 5, outside the tub.

Figure 2 is an enlarged sectional view of the area where the bearings and the drum shafts are mounted in a washing machine in accordance with the invention. In order to reduce the size of the Figure, the side plates or vertical walls of the tub, that is the cover 15 and the back of the body 14 are shown at a smaller distance from each other.

In accordance with the invention the first bearing support 20 is mounted on the side plate 1 5 (cover) of the tub from the outside towards the inside, whilst the second bearing support 30 is mounted on the other side plate (back of the tub body 14) from the inside towards the outside. The bearing supports are made of a moulded synthetic material. They have the shape of rotationally symmetrical bushings 21,31, mounted in a bore 22, 32 in the tub wall, an elastic O-ring 23, 33 providing water-tight sealing between the cylindrical wall of the bore and the wall of the bearing support, which for this purpose is formed with a peripheral groove.A shoulder 24, 34 on the outside of the cylindrical portion of the bearing support butts against a corresponding front surface 25, 35, formed on the tub wall around the bore 22, 32. The surface 25, which engages the shoulder 24 of the first bearing support 20, is disposed outside the tub. The surface 35, which engages the shoulder 35 of the second bearing support 30, is disposed inside the tub. Moreover, the bearing support 20 and the bore 22 receiving it have peripheral slots and pins 26 on their ends inside the tub, thus providing a "bayonet" coupling of the support in its bore.

The bearing supports 20 and 30 comprises a bearing recess 27, 37 with a cylindrical wall which is open towards the exterior of the tub, and is bounded by a partition 28,38 near the end of the support inside the tub. The bearing 40 is forced into said recess, whose wall and partition are formed with grooves 29, 39 for draining any leakage water or condensation. The openings of the recesses 27, 37 are restricted by a peripheral rim which serves to retain the bearing after it has been inserted into the support, insertion being possibel owing to the elasticity of the material from which the supports are moulded.

It is to be noted that the bearing support 20 has a recess 27 which is out of centre relative to its outer cylindrical surface 22. In the present invention in which the drive belt for the washing drum 4 is situated inside the tub, this arrangement of the bearing support 20 enables the belt tension to be adjusted by a displacement of the drum axis by adjusting the angular position of the bearing support in the bore in the tub wall.

Each bearing 40 receives a drum shaft 5, for example made of an aluminium alloy, onto which it is crimped. Inside the tub the shaft 5 terminates in a male conical portion 51 which is adapted to engage with a conical recess 52 formed in a flange 53 disposed in the centre of the corresponding side plate of the washing drum. The flange 53 is, for-example, riveted to the side plate of the drum, which is generally made of stainless- steel sheet. From the centre of the conical recess 52 of the flange a locating bush 54 projects, whose bevelled end engages a recess 55 in the shaft 5. The shaft 5 is hollow to permit the passage of a bolt 56, whose head is located outside the tub and whose thread co-operates with an axial thread formed in the flange 53, namely in the bush 54.

Around the shaft 5, and against its conical portion an elastic lip-seal 57 is arranged, whose lip engages with the rubs against the partition 28, 38 of the bearing support, inside the tub. Said seal provides water-tight sealing between the two parts which rotate relative to each other, that is the shaft 5 and the bearing support 20, 30.

It is to be noted that the shaft 5, its bearing 40, the seal 57 and the bearing support 20, 30 constitute an inseparable assembly, which is supplied as such in order to assemble or repair the washing machine.

Assembly of the drum and the tub of the washing machine proceeds as follows. When the main body 14 of the tub is in position, a bearing support 30 (with associated bearing, shaft and seal) is slid into the bore 32 in the centre of the back of the body 14. The drum 4 is then mounted and the flange 53 engages with the conical portion of the shaft 5. In the present example of a washing machine the belt 11 is passed around the drum. The bolt 56 can then be fitted into the bush 54 in order to secure the shaft and the flange to each other. The cover 1 5 of the tub is s subsequently fitted and secured to the tub body by means of the straps 1 6. The bearing support 20 (with associated bearing, shaft and seal) is slid into the bore 21 in the centre of the cover 1 5, so that the shaft 5 engages with the corresponding flange of the drum. For a complete insertion of the bearing support 20 the drum must be compressed between its two shafts. Finally, the bearing support 20 is locked against rotation by means of the pins 26, the bolt 56 is fitted and the belt 11 is tensioned by angular adjustment of the support 20 in its bore. Support 20 may alternatively be locked in position by fixing screws.

In order to replace the drum bearing in the support 20 its suffices to loosen the corresponding bolt 56, to unlatch the support (disengagement of the pins 26) and to withdraw the support in order to replace it by a support with a new bearing. In order to replace the bearing in the support 30 the tub cover 15 is removed and the drum 4 is taken out of the tub body after removal of the support 20. The bearing support 30, which has only been slid into its bore 32, is withdrawn together with the drum. After replacement of the support with the defective bearing, the machine is reassembled as described in the foregoing.

It will be seen that the two operations involving the bearing supports 20 and 30 are effected from the same side of the tub, so that prior to this only one panel of the parallelepiped housing 3 surrounding the tub should be removed.

Claims (7)

1. A laundry-washing machine comprising a tub for receiving the washing or rinsing water, inside which a laundry drum having a substantially horizontal axis can rotate, which drum is supported by two shafts, whose bearings are mounted in two respective removable bearing supports arranged in the tub wall, characterized in that first of the two bearing supports is axially retained on the tub wall, whilst the second bearing support has the form of a bushing with a shoulder.

which bushing is slid into a cylindrical recess in the tub wall until said shoulder butts against the inner side of said wall, said second bearing support being retained under the influence of the elastic force produced by an axial compression of the washing drum.

2. A washing machine as claimed in Claim 1, characterized in that the first bearing support has the shape of a bushing with an external shoulder, which bushing is slid into a cylindrical recess in the tub wall until said shoulder butts against the outer side of said wall.

3. A washing machine as claimed in Claim 1 or 2, characterized in that static sealing between the bearing supports and the tub wall is provided by an O-ring which is disposed in a peripheral groove in the cylindrical surface of the bearing support and which is compressed by the cylindrical surface of the recess receiving said support.

4. A washing machine as claimed in any of Claims 1 to 3, characterized in that each bearing support is made of a moulded synthetic material and, for receiving the bearing, comprises an axial cylindrical recess which is open towards the outside of the tube, whose back and inner periphery are grooved and whose opening is restricted by a projection behind which the bearing is fitted by force, the back of said recess constituting a partition which, at the inside of the tub, engages with the lip of a rotary seal mounted on each shaft.

5. A washing machine as claimed in any one of the Claims 1 to 4, characterized in that each shaft is fixed to its bearing and is coupled to the drum by means of a flange which is secured to the centre of each side plate of the drum, the corresponding shaft and flange being aligned by abutment of co-operating conical surfaces.

6. A washing machine as claimed in Claim 5, characterized in that each shaft is secured to its flange by means of a bolt which passes axially through the shaft and which is screwed into the flange.

7. A washing machine substantially as herein described with reference to the accompanying drawings.