WO2008080826A1

WO2008080826A1 - Drive unit for domestic clothes dryer

Info

Publication number: WO2008080826A1
Application number: PCT/EP2007/064112
Authority: WO
Inventors: Reinhard Heyder; Jörg SKRIPPEK
Original assignee: BSH Bosch und Siemens Hausgeräte GmbH
Priority date: 2006-12-27
Filing date: 2007-12-18
Publication date: 2008-07-10
Also published as: DE102006061526A1

Abstract

The invention relates to a drive unit for the operation of a domestic clothes dryer, comprising one at least almost horizontally rotatably mounted washer drum, which is driven by means of an electric motor. The high rotational speed thereof is geared down by an interposed gear reducer and is adapted to the rotational speed of the drum during the drying process. The inventive drive unit is characterized in that the drive motor is arranged stationary in the housing of the clothes dryer and that the gear reducer, which is arranged on a supporting arm, is rotatably arranged with the arm about the axis of the motor shaft. The preferred solution provides that a holder is formed in the end plate concentrically to the motor shaft, wherein the supported arm is held pivotally in the holder. Compared to known drive unites, the proposed solution for a clothes dryer provides the possibility to produce the device more economically as a whole. An important advantage of the inventive drive unit is that the oscillating elements for fastening the motor can be optimized without restrictions in regards\ to the decoupling effect thereof.

Description

Drive unit for a household tumble dryer

The invention is based on a drive unit for the operation of a household tumble dryer with an at least approximately horizontally rotatably mounted laundry drum which is driven by an electric motor whose high speed is reduced by an interposed countershaft and adapted to the speed of the drum during the drying process becomes.

The mechanical power transmission takes place in such a drive unit from the pinion of the drive motor to a large pulley, which is rotatably connected via a common axis with a counter gear. The drum is rotated by means of a looped around the drum shell drive belt, which is driven by the counter gear.

A drive unit with a countershaft together with the described reduction function is listed in DE 297 04 645 U 1. Characteristic of this drive unit is that the common axis of the gear, on which the large pulley and the counter gear teeth are rotatably mounted, is mounted at the free end of a support arm, which in turn is mounted on a separate support block. The bearing point of the support arm is arranged concentrically to the motor shaft of the drive motor. A tension spring acting on the free end of the support arm causes the belt or belts for the transmission of the drive forces to be tensioned in such a way that slippage during operation of the dryer is prevented. The position in which the support arm is pivoted thereby, will hereinafter be referred to as the clamping position.

In a drive unit according to EP 0 709 515 A1, the common axis with the large pulley and the counter gear is guided under spring tension axially parallel movable. The pivot points of the support arm, the common axis and the engine pinion are approximately on a straight line. With this arrangement, an improved power transmission and a safer compensation of the stuck in the system tolerances is achieved.

The above-described drive units have the common disadvantage that the respective construction requires a relatively large number of individual parts, which is associated with increased eco- business and organizational expenses. In particular, the assembly of the individual components requires a considerable amount of extra work time.

A structurally much simpler and therefore more economical solution is the utility model DE 80 1 1 829 U removed. The drive unit disclosed therein is characterized by a drive motor rotatably mounted about the axis of rotation of its motor shaft. The drive pulley of the belt drive is arranged on the outside of a bearing plate of the drive motor. With the drive pulley to this coaxially arranged friction wheel is rotatably connected. The friction wheel is pressed against the motor shaft and is also arranged on the end shield. The axles of the friction wheel and drive pulley are aligned parallel to the motor shaft and firmly positioned with respect to them. The drive belt encompassing the drum is tensioned by pivoting the engine as a whole, i. together with the bearing plate arranged on the friction wheel and the drive pulley, about an axis of rotation equiaxial to the motor shaft.

A similarly designed in construction and its operation drive unit is described in the patent DE 196 36 705 C2. The fastening device of the drive motor is equipped with receptacles in which the engine is pivotally mounted. The pictures are assigned to the end shields. For vibration isolation, the images of the fastening device are equipped with plastic bearings. The reduction unit with the pulley and the counter gear, which are on a common

Axis are arranged torsionally rigid, is mounted near the free end of a support arm. The axis of the reduction unit is aligned parallel to the motor shaft. The other end of the support arm is attached to a bearing plate. As with the drive unit described above, the reduction unit is pivoted together with the motor about the axis of the motor shaft in the clamping position.

The two drive units last described are structurally relatively simple in construction, and the number of items required is low. The disadvantage is that in each of these constructions, the vibrating elements are subject to higher wear with the result that it can come to a much higher noise level over the bearings after prolonged service life. In order to counteract this wear, as in the last-mentioned example, additional sliding bearings are used, which are arranged between the oscillating elements and the motor shaft. The principal and thus essential disadvantage consists in the fact that the vibrating elements as parts of the holding device at the same time fulfill the function of bearing bushes, over which the rotation of the motor is secured. This additional function means that the margins for designing the holding device and the vibrating elements are severely limited. In particular, it is not possible to optimally design the oscillating elements with respect to a vibration damping.

The invention has for its object to provide a drive unit for operating a clothes dryer, which can be realized according to the developed state of the art with simple design means and beyond the possibilities for structuring the engine mount extended and optimal decoupling allows, even after a long time Operating time remains effective.

According to the invention this object is achieved with a drive unit according to the features of claim 1. Further features and advantageous embodiments are contained in the respective subsequent subclaims, whose features can be used individually or in any combination with each other or with the features of claim 1.

According to the invention, the drive motor is arranged rotationally fixed in the housing of the tumble dryer, and the support arm with the common axis for the large pulley and the counter gear is arranged pivotably about the axis of the motor shaft. The support arm is pivotally mounted directly on the motor shaft or preferably in a

Bearing shield concentric to the motor shaft molded recording.

In a further developed embodiment of the invention, the support arm is fixed in clamping position on the bearing plate. In this embodiment acts on the free end of the support arm acting tension spring as an additional relief element that reduces the force on the vibrating elements.

The drive device according to the invention is characterized in comparison to those of the prior art in that the structural design is simpler, and the risk of wear on the motor mount is reduced. A rationalization effect is that no additional bearing for the engine mount is required. Another very important advantage of the drive unit according to the invention is that the oscillating elements are not simultaneously used as bearing bushes for the motor vehicle. - A -

Torwelle in the engine bracket act. This results in wide scope for both the construction of the engine mount and in particular for the construction of the vibrating elements.

The motor mount can be adjusted according to the installation situation, the selection of the constructive means are very wide limits. As vibration elements standard parts can be used or tailored to the specific application case and with respect. The decoupling effect optimally designed blocks. This has the advantage that the noise and the vibration transmission can be permanently reduced to a minimum.

The spatial arrangement and the attachment of the drive motor takes place in the drive unit according to the invention as in conventional devices usual in such a way that the motor shaft is aligned axially parallel to the axis of rotation of the laundry drum. Thus, a simple construction of the drive unit can be realized with a low power transmission with low wear of the drive belt. The drive unit according to the invention is characterized in that there are no further functional and thus constructive dependencies on further modules or components. The adaptation of the blocks to each other and the compensation of tolerances in the drive system via the pivotally mounted support arm. This results in both a simplification of the system as a whole and considerable advantages in the production of the device. The effort involved in mounting and adjusting the drive system is considerably reduced.

Using the example of two preferred drive units, the invention will be explained in more detail below with reference to the drawings. Show it:

1 shows a drive unit of a tumble dryer in a perspective view;

Fig. 2: such a drive unit in side view.

In Fig. 1, a drive unit for a tumble dryer is shown, wherein in the drawing only the essential elements for the following explanation have been included. The motor 1 for driving the drum and the blower, also not shown, is non-rotatably connected via fasteners 13 with the housing of the weighing schetrockners connected.

The bearing plate 2 of the drive motor 1 has a concentric with the motor shaft 4 formed circular receptacle 9 for pivotally mounted in the receptacle 9 supporting arm 3. During assembly, the support arm 3 is attached via the motor shaft 4 and secured by suitable means. The support arm 3 is a one-piece plastic part.

Near the free end of the support arm 3, a receptacle for the common axis 5 of pulley 8 and counter gear 7 is arranged. The large pulley 8, which is connected via a counter belt 16 to the motor pinion 6, and arranged between the bearing and the large pulley 8 counter gear 7, via which the laundry drum, not shown, is rotated by the drive belt 12 in rotation, by means of the common Axis 5 rotationally connected to each other.

The arrangement of the countershaft sprocket 7 between the large pulley 8 and the axle receiving in the support arm 3 causes a favorable power transmission. By suitable choice of the distances of pinion 7 and pulley 8 to each other and the Achsaufnah- me in the support arm 3, the tilting moment acting on the axle bearing can be minimized, which has a wear-reducing effect.

At the free end of the support arm 3 acts in the direction of filing a tension spring. Due to the spring tension of the support arm 3 is held permanently in a position in which the drive belt 12 is sufficiently tensioned.

In another embodiment, which is shown in Fig. 2, the support arm 3 in the

Clamping position bolted to the bearing shell. For this purpose, the support arm 3 has two concentric with the motor shaft 4 arranged slots 1 1. When mounting the device, the fastening screws 10 are loosely attached to hold the support arm 3 on the bearing shell and firmly screwed after pivoting of the support arm 3 in the clamping position. The countershaft is thus fixed on the bearing plate 2 reliable. The additional

Spring 15, which is suspended at the free end of the support arm 3 and whose second end is fastened to the device housing, has the task of reducing the force acting on the oscillating elements 14 in this embodiment.

In the illustrated exemplary embodiments (FIGS. 1 and 2), different fastening means 13 and oscillating elements 14 are illustrated. A very simple form is shown in FIG. 1. As a fastener 13 four feet are formed with screw holes on the motor housing, via which the motor 1 is attached directly to the device housing or on a support structure. The mounting feet 13 are arranged in a plane.

In the second exemplary embodiment (FIG. 2), the drive motor 1 is connected to the housing via two fastening plates 13 arranged at right angles to one another. On the motor side, the fastening device 13 has two shell-shaped formations which are adapted to the shape of the motor 1 and hold it at least partially comprehensively in the installed position by means of clamping pressure. Between the shell-like formations of the fastening device 13 and the motor 1, the Schwingelemen- te 14 are arranged, which are formed according to the specific application, and are optimized in particular with respect to the vibration damping effect.

The design of the fastening and oscillating elements 13, 14 is not limited to the illustrated embodiments. They are only examples of a virtually unlimited variety of design options.

reference numeral

1 . drive motor

2nd bearing plate

3rd support arm

4. Motor shaft

5. common axis

6. Motor pinion

7. Counter gear teeth

8. big pulley

9. Recording in the end shield

10. Mounting screws

1 1st slot

12. Drive belt

13. Fasteners

14. Oscillating elements

15. tension spring

16. Belts

Claims

claims

1 . Drive unit for a domestic laundry dryer with an at least approximately horizontally rotatably mounted laundry drum, which by means of a

Drum jacket looped drive belt of a counter gear pinion is rotatably displaceable, wherein the counter gear and a large pulley rotatably connected to each other via a common axis which is mounted near the free end of a support arm, and the pulley is in turn driven via a counter belt from the motor pinion of the drive motor , characterized in that the drive motor (1) is arranged rotationally fixed in the housing of the tumble dryer and the support arm (3) about the axis of the motor shaft (4) is pivotally mounted.

2. Drive unit according to claim 1, characterized in that in the bearing plate (2) concentric with the motor shaft (4) has a receptacle (9) for the support arm (3) is formed.

3. Drive unit according to claim 1, characterized in that the support arm (3) in the clamping position on the bearing plate (2) is fixable, e.g. by means of screws 10 which pass through in the support arm (3), concentric with the motor shaft (4) aligned long holes (1 1).

4. Drive unit according to claim 1, characterized in that the support arm (3) on the motor shaft (4) is pivotally mounted.

5. Drive unit according to claim 1, characterized in that the support arm (3) is a one-piece plastic part.

6. Drive unit according to claim 1, characterized in that the counter gear (7) between the axle receiving in the support arm (3) and the large belt disc (8) is arranged.

Drive unit according to claim 1, characterized in that fastening elements (13), e.g. Mounting feet or plates are integrally formed, by means of which the motor (1) is connected directly to the device housing or rotationally fixed by a Haltekon- construction.

8. Drive unit according to claim 1, characterized in that the drive motor (1) via a drive motor (1) at least partially encompassing fastening element (13) is rotationally connected to the device housing

9. Drive unit according to claim 1, characterized in that between the fastening elements (13) of the motor (1) and the device housing or the

Holding construction vibrating elements (14) are arranged.