GB2253861A

GB2253861A - Drive motor mounting in a washing machine

Info

Publication number: GB2253861A
Application number: GB9205527A
Authority: GB
Inventors: Bernd Wetzel
Original assignee: Individual
Current assignee: Individual
Priority date: 1991-03-20
Filing date: 1992-03-13
Publication date: 1992-09-23
Anticipated expiration: 2012-03-13
Also published as: GB9205527D0; ITMI920615A1; IT1254681B; ITMI920615A0; HK92995A; DE4109164A1; ES2052425B1; GB2253861B; ES2052425R; ES2052425A2; DE4109164C2

Abstract

In a washing machine comprising a front-loading laundry drum which is surrounded by a washing solution container (1) and is rotatably mounted in a support spider (2) carrying the container at its rear side a drum drive motor (10) is connected by a bearing member (9) to one arm (4) of the spider. A fastening web (5) is cast onto the one arm (4) of the spider (2) and for the predominant part is disposed within the outline of the container (1). An outrigger (11) is cast onto the bearing member (9) and is detachably connected to the web. The connection may be through screws (14, 15) or a dovetailed groove. <IMAGE>

Description

DRIVE MOTOR MOUNTING IN A WASHING MACHINE 2253861 The present invention

relates to a washing machine and has particular reference to the mounting of a drive motor in the machine.

A known washing machine comprises a laundry drum which is loadable from the front, is surrounded by a washing solution container and is mounted to be rotatable horizontally in a support spider carrying the container at the rear side. The drum drive motor includes a bearing member, which is connected with the motor housing (stator) and fastened to an arm of the spider, and drives the drum by way of a drive belt. For reduction in the components of and assembly steps for such a machine, DE-OS 31 32 211 discloses a simplified motor fastening in which, in place of fastening and adjusting parts to be specially welded onto the container casing, the motor bearing member is detachably fastened to a foot at an arm prolongation of the spider. This method of fastening also improves the noise behaviour 15 of the motor suspension, which is excited by hum noises of the motor.

A further improvement of the noise behaviour would still be desirable, z_ however, as well as a means of achieving a shape of the spider more compatible with, for example, manufacture by casting, in particular a shape in which the ratio of sand to cast material is more balanced 20 and allows the spider to be cast more cheaply.

According to the present invention, there is provided a washing machine comprising a support spider disposed at a rear side of the machine, a washing solution container supported by the spider, a laundry drum encircled by the container and having an access opening at a front side of the machine, the drum being mounted in the spider to be rotatable about a substantially horizontal axis, and a drive motor which is drivingly coupled to the drum by way of a drive belt and which comprises a housing provided with a mounting arm detachably connected to a mounting web at the spider, the web being formed integrally with one arm of the spider and disposed at least partly within an area outwardly bounded by notional connections between the ends of the arms of the spider.

In a preferred embodiment, the web is cast on said one arm of the spider and for the predominant or major part is disposed within the notional straight connections between the respective arm ends, while the mounting arm, in the form of an outrigger, is cast on at a bearing member of the motor housing. Since the web is disposed mainly between the arms, the area covered by the spider within the outer boundary determined by the connections is reduced by comparison with the prior art. Consequently, the spider can find room for casting in a smaller mould box and less sand is needed for the production of the casting mould. Although the corresponding area of the bearing member may be increased it nevertheless still finds room in a small mould box. As explained further below, the prerequisites for improvement in noise behaviour are also provided.

In simple preferred construction of the spider,. the web is formed by a one-sided enlargement of the end portion of said one arm of the spider. Such a shaping is non-critical in terms of casting technique and requires few additional cast-iron masses.

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n ' In further advantageous development, the bearing member and the outrigger are formed from one cast-iron piece. By comparison with known washing machines, in which - motors are used with bearing members of die-cast aluminium at the drive side, the construction of the bearing member, which is provided with a longer outrigger, from cast iron is more economical and appreciably more effective in respect of the noise damping. It has proved that the generation and transmission of noise can be appreciably reduced with a combination of spider with web and bearing member with outrigger, both of casti ron.

In an advantageous development, the outrigger can be connected with the web by way of fastening elements engaged in openings, for example an own bore with a screw or pin and a bore in the web and, to allow adjustment of the spacing of the motor drive axis or centre line from the rotational axis of the drum, a second bore with screw. For this purpose, a slot permitting pivotation of the motor about the first-mentioned screw or pin and thereby adjustment of the spacing between the motor and drum is provided for the adjusting screw in the web.

Alternatively, the bearing member can be detachably connected to the web by mechanically positively interengaging parts of the web and the arm. Such a shape-locking connection enables further. fastening elements, such as screws, washers and nuts, to be dispensed with, -so that this method of connection is also more economical than in the case of the state of the art.

1k According to a further development of the invention, this connection can be such that the mounting arm is retained in a predetermined assembled position by the tension of the drive belt. In that case, the interengaging parts should preferably have a sufficiently close fit so that the connection does not tend to rattle and thereby possibly generate noise in the container system. The connection can be formed by a dovetail-like guide, which can provide a connection without noteworthy risk of noise generation due to rattling.

For preference, the guide narrows conically in direction towards the assembled position. The assembled position is then determined by a secure interengagement which does not permit rattling even if tolerances are not otherwise very close. The narrowing can have an angle at most equal to the critical angle for self-locking of the chosen material couple. The motor can then be mounted in self- retaining manner without further fastening elements in the guide by a blow in direction towards the assembled position. The drive belt, which is subsequently drawn onto a pulley of the drum and a drive pinion of the motor, then acts to resist detaching of the connection. 20 The interengaging parts of the mounting am and the web can be additionally secured by detachable key means extending transversely of the guide. Embodiments of the present invention will now be mo.re particularly described by way of example with reference to the accompanying drawings, in which:

i Fig. 1 is a rear elevation of the washing solution container of a first drum washing machine embodying the invention, showing a support spider, drive motor and drive belt pu 11 ey, Fig. 2 is a detail view, to an enlarged scale, of the motor fastening region II in Fig. 1, but of a second washing machine embodying the invention; and Fig. 3 is a cross-section of the fastening region shown in Fig. 2, along the line IIIIII of Fig. 2.

Referring now to the drawings, there is shown in Fig. 1 a washing solution container 1 of a front-loading washing machine, the container being fastened to a star-shaped support spider 2. Rotatably mounted in the hub 3 of the spider is a bearing axle of a washing drum (not shown) arranged in the container 1. One of the downwardly directed arms, in particular the arm 4, of the spider has a one-sided enlargement at its end, the enlargement serving as a fastening web 5 for a drive motor 10. The web 5 is disposed within the outline of the container 1, unlike the foot-like arm prolongation present in the prior art machines. The motor housing has a bearing member 9, which is disposed at the drive output side and is penetrated by a shaft carrying a drive pinion 12. The pinion 12 is partially encircled by a drive belt 6, which also parily extends around a large. drive belt pulley with which the laundry drum is connected to be secure against relative rotation.

Two holes, of which one is a threaded bore (not shown) and the other an elongate hole 13, are arranged in the web 5.

1 X( - 6 X Correspondingly, two bores, which are penetrated by screws 14 and 15, are arranged in an outrigger 11, which is cast on the bearing member 9 and extends into the outline area of the container 1 and up to the web 5. The screw 14 is threadedly engaged in the threaded bore of the web, whilst the screw 15 extends through the unthreaded elongate hole 13 and is fastened at the rear side of the web 5 by a nut. The angular setting of the outrigger 11 and thereby the spacing of the centre lines of the motor 10 and the belt pulley 7 can be adjusted at the hole 13. In this manner, the drive belt 6 can be tensioned.

An alternative embodiment is illustrated in Figs. 2 and 3, in which the outrigger 11 is connected with the web 5 by mechanically interengaging parts. This connection is indicated by dashed lines in Fig. 2. More particularly, the web 5 is provided on its side directed towards the outrigger 11 with a guide strip 16, which,for example, extends radially relative to the centre line of the large pulley 7. A guide groove 17 complementary thereto is, for example, formed in that side of the outrigger 11, which faces the web 5. The groove is so disposed relative to the length direction of the outrigger 11 that the motor 10 is disposed close to the wall of the container 1 when the strip 16 is located in the groove 17. If the strip 16 and the groove 17 are slightly offset relative to the afore mentioned radial direction, the tension of the drive belt 6 then causes a canting which enhances the rigidity of the connection.

The strip 16 and the associated guide groove 17 are preferably shaped so that the web and the outrigger are movable relative to each other in only one direction, namely in that direction of the axes of 1 the groove and strip which is towards the centre line of the pulley 7. The illustrated dovetail form of guide is of advantage, because the play transversely to the direction of the principal axes, can be kept very small. Moreover, such a guide is immovable in direction normal to the contact surfaces of the outrigger 11 and the web 5.

The connection can be such that the play between the strip and the groove becomes less in direction towards the assembled position, i.e. a conical narrowing is provided. If this narrowing has an angle which is at most equal to the critical angle for self-locking of the relevant material couple, then, after introduction of the strip into the groove, a light blow with a rubber hammer in guide direction should suffice to produce a stable assembled position of the motor relative to the support spider 2.

If the stability of this method of assembly should be in doubt in a particular case, the connection can be secured by a key or notch locking extending in the manner of the dashed lines in Fig. 3. Such a key or notch locking can also serve for securing an assembled position which produces a desired tension in the drive belt 6. In that case, the strip 16 and the groove 17 are not necessarily congruent over their entire length. Rather, the belt 6 can be tensioned initially through displacement of the outrigger 11 relative to the web 5 in a direction away from the centre line of the pulley 7 before the key or notch locking is effected.

The use of a resilient drive belt 6, in which the belt tension can contribute to securing of the assembled position, is also possible for the case of an assembly without specific provision for tension adjustment.

Claims

4 ( 1. A washing machine comprising a support spider disposed at a rear side of the machine, a washing solution container supported by the spider, a laundry drum encircled by the container and having an access opening at a front side of the machine, the drum being mounted in the spider to be rotatable about a substantially horizontal axis, and a drive motor which is drivingly coupled to the drum by way of a drive belt and which comprises a housing provided with a mounting arm detachably connected to a mounting web at the spider, the web being formed integrally with one arm of the spider and disposed at least partly within an area outwardly bounded by notional connections between the ends of the arms of the spider.
2. A washing machine as claimed in claim 1, wherein the web is formed as an enlargement at one side of said one arm of the spider.
3. A washing machine as claimed in claim 1 or claim 2, wherein the motor housing comprises a bearing member of cast iron, the mounting arm being formed integrally with the bearing member.
4. A washing machine as claimed in any one of the preceding claims, wherein the mounting arm is detachably connected to the web by way of fastening elements engaged in openings, one of the fastening elements being adjustable to permit adjustment of the spacing of a drive axis of the motor from the axis of rotation of the drum.
5. A washing machine as claimed in any one of claims 1 to 3, wherein the mounting arm is detachably connected to the web by way of mechanically interengaging parts of the arm and the web.

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6. A washing machine as claimed in claim 5, wherein the mounting arm is held in a predetermined position relative to the web by the tension of the drive belt.
7. A washing machine as claimed in claim 5 or 6, wherein the interengaging parts define a guide path which in longitudinal direction is open only at an end thereof towards the axis of rotation of the drum.
8. A washing machine as claimed in claim 7, wherein the guide path so tapers inwardly as to reduce play between said interengaging parts in a predetermined position of the mounting arm relative to the web.
9. A washing machine as claimed in claim 8, wherein the angle of the taper is at most equal to the critical angle for self-locking of the parts.
10. A washing machine as claimed in claim 7 when dependent on claim 5, comprising key means extending transversely of the guide path.to locate the mounting arm in a predetermined position relative to the web.
11. A washing machine substantially as hereinbefore described with reference to Fig. 1 of the accompanying drawings.

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12. A washing machine substantially as hereinbefore described with reference to Figs. 2 and 3 of the accompanying drawings