WO2016016114A1

WO2016016114A1 - Domestic laundry treating machine with a washing drum driven by an electric motor and mounting method

Info

Publication number: WO2016016114A1
Application number: PCT/EP2015/066973
Authority: WO
Inventors: Tom Weber
Original assignee: BSH Hausgeräte GmbH
Priority date: 2014-07-30
Filing date: 2015-07-24
Publication date: 2016-02-04
Also published as: CN106414833A; EP3175030A1; DE102014214949A1; CN106414833B; DE102014214949B4

Abstract

The domestic laundry treating machine according to the invention is preferentially a front-loading washing machine. Said machine has a washing drum (2) driven by an electric motor and a belt drive between the washing drum (2) and the electric motor, in which the washing drum (2) is firmly connected to a drive shaft (3), and the drive shaft (3) is connected to a pulley (12) of the belt drive, wherein the pulley (12) is provided with a flange (11) having an internal thread (10) in the region of the connection to the drive shaft (3). In addition, the end (8) of the drive shaft (3) facing away from the washing drum (2) is preferentially provided with a shallow pot-like depression (13) and has an external thread (9) engaging in the internal thread (10). Moreover, both threads (9, 10) are connected non-detachably, in particular bonded, to one another.

Description

Household laundry treating machine having a laundry drum drivable by an electric motor and method of assembling

The invention relates to a household laundry treatment machine with a drivable by an electric motor laundry drum and a belt transmission between the laundry drum and electric motor, wherein the laundry drum is fixedly connected to a drive shaft and the drive shaft is connected to a pulley of the belt drive. The invention also relates to a method for

Mounting such a machine.

Increasingly, modern household laundry treatment machines, especially washing machines, equipped with vibrating systems that include a non-destructive no longer openable tub, such as to replace the laundry drum. This is related to that modern

Constructions of vibrating systems have become steadier and suffer in daily operation increasingly rare defects. Should a defect nevertheless occur, it becomes more economical to replace the entire oscillating system instead of replacing individual parts or assemblies. This fact has led to the connection between

To rationalize drive shaft and pulley, for which a detachable connection has always been sought. Therefore, a household laundry treating machine described at the outset has become known from DE 10 2010 062 520 A1, in which it is no longer considered necessary to make this connection non-destructively detachable, so that a more rational construction was also found at this point. For this purpose, according to the proposal, a screw connection was completely dispensed with, because such had required an additional positive connection for the safe transmission of torque (see paragraph [0002]). The solution was seen in that the pulley on the drive shaft

non-destructively arranged non-detachably, in particular welded. Such Welded connection can safely transmit the required torque, greatly reduces the design effort for this connection and must never be solved under the above premise anyway.

Unfortunately, this compound still has significant disadvantages. For example, when mounting the pulley, make sure that the pulley is absolutely perpendicular to the axis of the drive shaft without additional guidance. In fact, prior to welding, tilting of the disk is possible, which can only be prevented by a more complex mounting device. Since it is at the

Drive shaft is solid material that requires considerably more energy to melt in the welding process than the existing pulley, it must be feared that the softer sheet material is already melted away before the solid material of the drive shaft is melted binding and can get a material connection with the sheet material. Furthermore, the

proposed construction too small a distance of the weld to

Rolling, which therefore can take a too high heat input during welding and threatens to deform or its fat filling is lost. Finally, the proposed construction does not provide a sufficiently large contact surface for other cohesive connections, z. B. gluing or soldering. At this low

Contact surface would be such, for welding alternative connection not stable enough against the required transmission torque.

Other welded joints at this point are known from DE 7 004 816 U and DE 10 2008 013 200 A1. However, they relate to hollow shafts and are only used to attach a flange to the hollow shaft, to which the

Belt pulley is fastened by means of several screws or only for fixing a flange to a wheel disc, corresponding to the pulley of the machine described above. This flange is fixed by a central screw with a shaft and held against rotation by a groove / wedge connection. The respective disadvantages apply accordingly, in particular the more complex

Presentation. The present invention has for its object to find a suitable for the aspects described above construction of a cohesive - non-destructive unsolvable - connection between the drive shaft and the pulley. This object is achieved by a household laundry treatment machine of the type described above, which features the characteristics of the

Claim 1, and by an assembly method for such a machine according to the features in the characterizing part of claim 5 or 7.

In the laundry treatment machine according to the invention, therefore, the pulley is provided in the region of the connection to the drive shaft with a flange with internal thread. Furthermore, the direction away from the laundry drum end of the drive shaft, which is preferably provided with a shallow cup-like depression, an engaging in the internal thread external thread. And the two threads are unsolvable, namely cohesively, interconnected and serve only the positionally secure preparation of the compound and the inclusion of a portion of the rotational forces occurring. In the method of assembling such a machine, the internal thread of the flange of the pulley on the external thread of the outer end of the inserted into the bearing drive shaft with hard stop

screwed. After that, the pulley already sits securely and perpendicular to the axis of the drive shaft. Then the laundry drum

pioneering ends of the drive shaft and the flange, preferably the free annular surfaces, welded or soldered together so that shaft and washer can transmit all the torques occurring during operation of the machine absolutely safe. As an alternative to welding or soldering, an adhesive may be applied to the external thread of the outer end of the drive shaft inserted into the bearing and then the internal thread of the flange of the pulley can be screwed on with a hard stop. The bond requires only a short curing time and is already secured by the threaded connection during this time.

This solution has several advantages over the prior art.

In particular, the preparation of the drive shaft by a on of the Laundry drum pioneering end with a shallow pot-like recess creates at the later weld a component that like the flange of the

Pulley can absorb heat at the same speed and Mende. Therefore, both components will melt at the same time and flow into each other. This is the basis for a reliable connection. Before, the threaded connection automatically ensures the right-angled position of the pulley to the axis of the drive shaft. Due to the flange shape of both components to be joined together, the heat is introduced at a remote location from the rolling bearing and the rolling bearing protected. In addition, small melt zones are sufficient for the cohesive connection because the threaded connection already takes over part of the torques. The construction allows to adjust the

transmissible moments also an insertion of an axial forces generating

Spring washer. Finally, other cohesive bonding methods such as bonding and soldering are applicable, in which case the rolling bearings are protected against too high heat input.

From these points of view, it is advantageous if the flange and the cup-like depression of the laundry drum pioneering free annular surfaces which are at least approximately in a common plane and are inextricably linked together by means of welding or soldering. This can take place in particular in a weld remote from the rolling bearing

Heat input together with the small melting zones of spot welds on the ring surfaces best protect the rolling bearing.

[001 1] If the drive shaft at least on the laundry drum

wegweisenden end is mounted on a roller bearing and between the outer ring of the bearing and the washing drum facing the contact surface of the

Pulley is arranged a spring ring, an additional axial force can be generated, which applies a part of the transmission torques and of the

Keep entanglements away.

The features of the dependent claims can - as far as this is technically not excluded - with each other and / or with others from the following Description disclosed features can be combined with each other without departing from the invention.

Based on that shown in the attached drawing

Embodiment, the invention will be explained in more detail below. The drawing shows in Fig. 1, the axial cross section of a bearing portion of a drive shaft for a flying support of a laundry drum in a front loader washing machine and in Fig. 2 is an exploded view of the connecting portion of the outer

End of the drive shaft with the pulley in the situation just before joining the internal thread with the external thread.

The rear wall 1 of a laundry drum 2 mounted in a - here a plastic tub - mounted laundry tub 2 is fixedly connected in Fig. 1 with a drive shaft 3. From the tub, only the part is shown here, in which the bearing housing 4 is integrated on its rear wall. Here, the bearing housing 4 is pierced for the drive shaft 3, which is mounted together with the laundry drum 2 in this bearing housing 4 on two rolling bearings 5 and 6 on the fly. In this case, the inner roller bearing 5 is protected by a shaft seal 7 - here only schematically indicated - against liquid from the tub. The drive shaft 3 has at the bearings heels that the seat of

Defining roller bearings 5 and 6 during pressing. Another paragraph at the outer end of the drive shaft 3, which is the direction away from the laundry drum 2 end 8, contains an external thread 9, which in an internal thread 10 on the flange 1 1 of

Pulley 12 engages. The pulley 12 is connected in a manner not shown here via a drive belt with a pinion of an electric motor. The end 8 is frontally provided with a pot-like recess 13 through which a

The two annular end faces 15 and 16 of the flange 1 1 and the edge portion 14 are at least approximately in a plane and thus can easily from a weld 17 together be recorded, of which about three pieces or more evenly distributed on the end faces 15 and 16. Instead of these welds 17, the two end faces 15 and 16 may also be welded together in a closed annular manner.

For mounting this part of the machine are first with the

External thread 9 provided drive shaft 3 is inserted into the bearing housing 4 and the shaft seal 7 and the bearings 5 and 6 are pressed. According to FIG. 2, the internal thread 10 of the flange 11 of the pulley 12 is then screwed onto the external thread 9 with a hard stop. To apply higher axial forces a spring ring 18 is inserted between the inner ring of the outer roller bearing 6 and the bearing facing surface of the pulley 12, which is completely pressed when screwing the flange 1 1. Subsequently, the free ones

End faces 15 and 16 by means of welding points 17 welded together.

Alternatively, for welding, the assembly process by a

Gluing technique can be varied instead of welding. This is done after the

Process step of pressing the bearings 5 and 6, the external thread 9 is covered with a thin adhesive layer, and then only the internal thread 10 of the flange 1 1 screwed. The adhesive must be adjusted so that it fits with the

Threaded surfaces enters an intimate adhesive contact. Optionally, a spring ring 18 can be inserted here, but welding after unscrewing is unnecessary. Rather, the glue has to be given time to cure, but until the next step in the assembly of the laundry treatment machine, the

burdening compound according to the invention - not explained here in detail -, anyway flows.

The invention is also intended to the kinematic reversal of

Extending connecting portion, in which the thread of the drive shaft 3 at the

Inside the thin-walled portion 14 of the pot-like recess 13 is mounted. For this purpose, however, the pot-like recess 13 should be slightly deeper than in the example shown. At the same time then the thread would have to be attached to the flange 1 1 on the outside thereof to correspond to the thread of the end 8. As in this example, but the attachment of the spring ring and the welds For a more complicated shaping of the flange area of the pulley, the example shown is favored with regard to the distribution of the threads on the inside and outside.

LIST OF REFERENCE NUMBERS

1 rear wall of Wäschetronnnnel

2 laundry drum

3 drive shaft

4 bearing housing

5 inner bearings

6 outer bearing

7 shaft seal

8 outer end of the drive shaft

9 external thread

10 internal thread

1 1 Pulley flange

12 pulley

13 pot-like depression

14 thin-walled edge area

15 face of the flange

16 end face of the pot-like depression

17 spot welds

18 spring washer

Claims

Godfathers

1 . Household laundry treatment machine with a driven by an electric motor laundry drum (2) and a belt transmission between

Laundry drum (2) and electric motor, wherein the laundry drum (2) is fixedly connected to a drive shaft (3) and the drive shaft (3) is connected to a pulley (12) of the belt drive, characterized

characterized in that the pulley (12) is provided in the region of the connection with the drive shaft (3) with a flange (1 1) with internal thread (10), that the end facing away from the laundry drum (2) (8)

Drive shaft (3) into the internal thread (10) engaging external thread (9), and that the two threads (9, 10) are non-detachably, namely materially bonded, interconnected.

2. Machine according to claim 1, characterized in that the of the

Laundry drum (2) pioneering end (8) of the drive shaft (3) with a flat pot-like recess (13) is provided.

3. Machine according to claim 2, characterized in that the flange (1 1) and the cup-shaped recess (13) of the laundry drum (2) pioneering free annular end faces (15, 16) which lie at least approximately in a common plane and are permanently connected by welding or soldering.

4. Machine according to one of claims 1 to 3, characterized in that the permanent connection is realized by means of spot welding (17).

5. Machine according to one of claims 1 to 4, characterized in that the drive shaft (3) at least on the laundry drum (2) pointing away end (8) is mounted on a rolling bearing (6) and between the inner ring of the Rolling bearing (6) and the laundry drum (2) facing contact surface of the pulley (12) has a spring ring (18) is arranged.

6. A method for assembling the machine according to one of claims 1 to 3, characterized in that on the external thread (9) of the outer end (8) of the inserted into the bearing drive shaft (3), the internal thread (10) of the flange (1 1 ) of the pulley (12) with a hard stop

is screwed on and then from the laundry drum (2) pointing away ends of the drive shaft (3) and the flange (1 1)

welded or soldered together.

7. The method according to claim 6, characterized in that after the

Screwing the pulley (12) of the laundry drum (2) pioneering free annular end faces (15, 16) of the flange (1 1) and the drive shaft (3) welded or soldered together.

8. A method for assembling the machine according to claim 1 or 2, characterized in that on the external thread (9) of the outer end (8) of the introduced into the storage drive shaft (3) applied an adhesive and then the internal thread (10) of the flange (1 1) of the pulley (12) is screwed with a hard stop.

9. The method according to any one of claims 6 to 8, characterized in that before screwing the pulley (12) according to a spring ring (18)

Claim 5 is pulled on the drive shaft (3).