WO2008138766A1

WO2008138766A1 - Fan for a clothes dryer

Info

Publication number: WO2008138766A1
Application number: PCT/EP2008/055350
Authority: WO
Inventors: Stefan Holzer
Original assignee: BSH Bosch und Siemens Hausgeräte GmbH
Priority date: 2007-05-11
Filing date: 2008-04-30
Publication date: 2008-11-20
Also published as: DE102007022097A1

Abstract

The invention relates to a fan for an appliance used for the care of clothes, comprising a spiral housing (2), in which a radial fan wheel (3) is rotatably disposed, and an intake air duct (4), which is configured for axial air intake, wherein the intake air duct (4) comprises a screen (5) having an air intake opening (6) for axial air intake, the screen covering the front of the radial fan wheel (3), and a separating wall (13), which is disposed on the spiral housing (2) and extends in an open space (11) of the radial fan wheel (3) delimited by the radially disposed blades (31).

Description

Blower for a tumble dryer

The invention relates to a blower for a domestic appliance for the care of laundry items, in particular a clothes dryer, with a spiral housing in which a radial impeller is rotatably mounted, and an intake air duct, which is designed for axial air intake.

Such a fan is known from EP 0 702 105 B1.

In a domestic appliance for the care of laundry, in particular in the form of a tumble dryer, a ventilation system is required, which is sufficiently robust against

Pollution, especially leaching, is and a sufficiently high

Blower pressure ensures even with prolonged use. Today's dryers use forwardly curved impellers or blades on the impeller, since these are relatively quiet and can generate a high airflow. However, the characteristic of such blowers is relatively flat. This means that with increasing pressure, for example, due to excessive loading of the dryer and / or many lint in the

Sieve or can occur in the condenser, the amount of air produced decreases relatively strong.

Steeper characteristics and thus higher pressures can in principle with backward curved

Impellers or blades are achieved, however, such an impeller is relatively expensive and requires a higher speed from a forward curved impeller.

It is an object of the present invention to provide a blower, which can be realized inexpensively and is relatively quiet in operation and can transport high amounts of air.

This object is achieved by a blower having the features of claim 1.

An inventive blower for a domestic appliance for the care of laundry comprises a spiral housing in which a radial impeller is rotatably arranged. Of

Furthermore, the fan comprises an intake air guide, which is designed for axial air intake. The intake air guide comprises a diaphragm which blocks the radial Fan wheel covers the front. The diaphragm has an air intake opening for axial air intake. Furthermore, the intake air guide comprises a partition wall arranged in the volute casing, which wall extends into a free space of the radial impeller.

The free space is virtually bounded radially by the inwardly oriented ends of the blades and thus represents a cylindrical cavity. The partition thus protrudes into this particular cylindrical cavity of the radial impeller. This embodiment of the intake air duct of the fan allows a relatively quiet operation and, moreover, the promotion of large amounts of air can be ensured. In addition, the production can be relatively inexpensive.

Preferably, the free space in the radial impeller is divided by the dividing wall into two subspaces.

It is preferably provided that the air intake opening is arranged in the aperture coaxial with the axis of rotation of the radial fan impeller. The partition is preferably arranged asymmetrically to this axis of rotation.

In principle it can be provided that the partition wall and / or the air intake opening are arranged asymmetrically to the axis of rotation of the radial impeller.

Just by the very simple designed intake air with the partition and the aperture with the air intake a significant improvement in terms of promoted air flow and noise during operation of the fan can be achieved.

The air intake opening and the partition wall are geometrically preferably arranged within the distance between the axis of rotation and a free space end of a blade.

In principle, can be created by the arrangement of the partition and the air intake and a very compact and space-saving design. Preferably, the partition is a flat plate. This allows a particularly simple design, whereby the production and assembly of this component can be done with little effort.

The dividing wall is preferably fixedly positioned and the blades of the radial impeller are arranged to be movable relative to this dividing wall and in particular to be arranged circumferentially around the dividing wall. The partition thus preferably has smaller dimensions than the maximum inner diameter of the radial impeller.

In particular, the dimensioning of the partition wall is always designed so that it is always smaller depending on their positioning in the free space of the radial impeller than a rectilinear connection path between two facing the free space

Ends of opposite blades, in extension of a line through the

Partition wall.

Preferably, the diaphragm forms a wall of the spiral housing. The aperture is multifunctional in this embodiment. As a result, a material and thus a weight saving of the fan can be made possible.

In addition, the simple accessibility to the internal radial impeller can be achieved by such a configuration, as is accessible by removing the aperture of this radial impeller.

In particular, the panel is formed as a flat plate, which constitutes a side wall of the spiral housing.

Preferably, the diaphragm is detachably arranged on the spiral housing. This allows a non-destructive and reversible feasible assembly and disassembly can be achieved. It is preferably provided that the diaphragm is screwed to other housing parts of the spiral housing.

It can be provided that the diaphragm is designed as a separate component to the partition wall. In this embodiment, the partition is arranged and mounted separately. It is preferably provided that the diaphragm and the partition wall are integrally formed. Through this design, manufacturing tolerances and mounting tolerances can be minimized. In addition, both the production and assembly can be done much faster.

The panel and / or the partition may be formed, for example, as sheet metal parts.

It proves to be preferable if the panel and / or the dividing wall are designed as plastic parts, in particular as injection-molded parts. Particularly advantageous is an embodiment as an injection molded part in a one-piece design of the panel with the partition.

Preferably, the blades of the radial impeller are curved in the direction of rotation of the radial impeller. Such forward curved blades once again positively contribute to minimizing noise in the operation of the fan and generating a high airflow. In particular, in a configuration of the fan with an inventive intake air guide and forward curved blades and a steeper characteristic can be achieved, which means that even with increasing pressure, the delivered air flow is still relatively large.

Preferably, the radial distance between an end of a blade remote from the free space and an inner side of the spiral housing in the delivery region of the fan is less than 4 mm, in particular 3 mm. The gap is therefore relatively small.

By means of the blower, with a relatively small radial fan wheel, in particular with forward curved blades and a very simply designed intake air duct, a considerably higher pressure than with conventional blowers can be achieved even at a relatively low speed of the blower. Even with an asymmetric arrangement of the air intake, a related improvement can be achieved. If not so high pressures are required, the fan motor speed can be reduced. With increasing size of the air intake opening, the delivered volume flow can be increased. Due to the possibility of reducing the engine speed, the life of the fan can be increased and, where appropriate, a structurally simplified design of the transmission are possible. In addition, the required space can be reduced. In particular, it can be prevented that the amount of air delivered does not decrease as much as with conventional blowers even with increasing leaching. This is particularly advantageous in tumble dryers, where compared to conventional technology, a smaller lint filter is provided.

Since the volume flow can be set relatively accurately in such a fan, can also result in optimization approaches for a drying process of a clothes dryer.

Preferably, with the blower according to the invention, it is possible, for example at a rated speed of about 2850 rpm, to increase the volume flow from a value of 0 m ³ / h at a freely discharging pressure of about 2300 Pa with a continuously decreasing discharge pressure to a value of zero Pa increases to a volume flow of about 300 m ³ / h.

Embodiments of the invention are explained in more detail below with reference to schematic drawings. Show it:

Fig. 1 is a schematic side view of a first embodiment of a blower according to the invention; and

Fig. 2 is a schematic side view of another embodiment of a blower according to the invention in an open state.

In the figures, identical or functionally identical elements are provided with the same reference numerals.

In Fig. 1, a blower 1 is shown for a designed as a tumble dryer or washer dryer domestic appliance in a simplified side view, which is coupled to a process air flow of the domestic appliance. In the operation of the household appliance can by the activated fan 1 process air, especially in a process air circuit, are performed.

The blower 1 comprises a spiral housing 2 in which a radial impeller 3 is rotatably arranged. This radial impeller 3 is rotatable about an axis A in the plane of the figure. The direction of rotation is counterclockwise. The radial impeller 3 comprises a plurality of forward curved blades 31, only some of which are shown in FIG. 1 by way of example only. The blades 31 extend perpendicular to the plane of the figure, whereby a cylindrical cavity is formed in the interior of the radial impeller 3, which is quasi bounded by the ends of the blades 31 facing the axis of rotation A, and is referred to as free space 11.

In addition, the blower 1 comprises an intake air guide 4, which is associated with a diaphragm 5. The panel 5 is formed substantially flat in the embodiment and arranged to the front cover of the radial fan 3. The aperture 5 forms a side wall of the spiral housing 2. The aperture 5 is detachably arranged on the remaining part of the spiral housing 2, in which, for example, screw 7, 8, 9 and 10 are provided.

The aperture 5 comprises an air intake opening 6, through which an axial air intake of the blower 1 is made possible. As a result of the axial air intake of the blower 1, air is drawn through the air intake opening 6 into the interior of the spiral housing 2 virtually perpendicular to the plane of the figure during operation of the blower 1. The air intake opening 6 is arranged in the embodiment of FIG. 1 so that it is formed coaxially to the axis A.

In addition, the intake air guide 4 comprises a partition wall, not shown in FIG. 1, which is designed as a flat plate and is arranged in the interior of the fan. In particular, this partition wall is arranged in the free space 11 of the radial impeller 3. The partition thus divides this space 1 1 in two subspaces. The partition is further dimensioned so that their dimensions are in a straight-line configuration smaller than the connecting distance between two the free space 1 1 facing ends of blades 31 in extension of an imaginary line through the partition. In a conveying region in which the radial impeller 3 is arranged as close as possible to the inside of the spiral casing 2, the minimum distance d has a value of about 3 mm.

In Fig. 1 a side view is shown, in which the aperture 5 is arranged on the spiral housing 2. As a result, the components of the radial impeller 3, the blades 31, etc. arranged in the volute casing 2 are also indicated by dashed lines only.

For optimized flow guidance, flow nozzles, not shown, may additionally be arranged inside the spiral housing 2. Due to the design of the intake air guide 4 with the air intake opening 6, the diaphragm 5 and the partition, a specified air flow in the spiral housing 2 can be made possible. For this purpose, a sucked on the air intake opening 6 working stream is due to the separation of the free space 11 through the partition only in the lying behind the air intake opening part of this space 1 1 promoted and further transported by the rotation of the radial impeller 3 and conveyed out of the radial impeller 3 , In the volute casing 2, however, this working flow is then introduced again into the radial impeller 3 due to fluidic effects, namely into the second subspace of the free space 11, into which the air intake opening 6 does not open. This working flow is then conveyed through this second subspace and fluidly conveyed by the movement of the radial impeller 3 so that it emerges as a power flow from a discharge blower 12 of the spiral housing 2 to the outside.

In Fig. 2, another embodiment of a blower 1 is shown in a side view, wherein in contrast to the illustration of FIG. 1, the aperture 5 is removed. In this embodiment, it is further provided that both the air intake opening 6 and the partition wall 13 shown are arranged asymmetrically to the axis of rotation A. Nevertheless, both the air intake opening 6 and the partition wall 13 within a radial distance r between the axis of rotation A and the free space 1 1 facing the end of the blades 31 are arranged. The partition wall 13 separates this free space 11 in a first subspace 1 1a and a second subspace 11 b. It can be provided that the partition wall 13 and the diaphragm 5 are formed as separate components. In particular, however, it is provided that the intake air guide 4 comprising the components of the partition wall 13 and the diaphragm 5 is formed as a one-piece injection-molded part.

A corresponding embodiment of this intake air duct 4 may also be provided in the embodiment according to FIG. 1. Since the aperture 5 is not present in the embodiment according to FIG. 2, the air intake opening 6 actually does not actually exist here, and the dashed representation of this air intake opening 6 is only intended to clarify the position when the aperture 5 is mounted.

The partition 13 is arranged stable in position and the radial impeller 3 rotates about this partition wall thirteenth

Claims

claims

A blower for a domestic appliance for the care of laundry, comprising a spiral housing (2) in which a radial impeller (3) is rotatably mounted, and an intake air guide (4), which is designed for axial air intake, characterized in that the Intake air guide (4) comprises a the radial impeller (3) front covering aperture (5) with an air intake opening (6) for axial Luftansagung and in the spiral housing (2) arranged partition (13), which in one of the through radially arranged blades (31) limited free space (11) of the radial impeller (3) extends.

2. Blower according to claim 1, characterized in that the partition wall (13) divides the free space (1 1) into two subspaces (1 1 a, 1 1 b).

3. Blower according to claim 1 or 2, characterized in that the partition wall (13) and / or the air intake opening (6) asymmetrically to the axis of rotation (A) of the

Radial fan blades (3) are arranged.

4. Blower according to one of the preceding claims, characterized in that the air intake opening (6) coaxial with the axis of rotation (A) of the radial impeller (3) is arranged.

5. Blower according to one of the preceding claims, characterized in that the air intake opening (6) and the partition wall (13) within the distance (r) between the axis of rotation (A) and the free space (1 1) facing the end of a blade (31 ) are arranged.

6. Blower according to one of the preceding claims, characterized in that the partition wall (13) is a flat plate.

7. Blower according to one of the preceding claims, characterized in that the partition wall (13) is fixedly positioned and the blades (31) are arranged circumferentially around the partition wall (13).

8. Blower according to one of the preceding claims, characterized in that the diaphragm (5) is a wall of the spiral housing (2).

9. Blower according to one of the preceding claims, characterized in that the diaphragm (5) is detachably arranged on the spiral housing (2).

10. Blower according to one of the preceding claims, characterized in that the diaphragm (5) is formed separately from the partition wall (13).

11. Blower according to one of claims 1 to 9, characterized in that the diaphragm (5) and the partition wall (13) are integrally formed.

12. Blower according to one of the preceding claims, characterized in that the diaphragm (5) and / or the partition wall (13) are formed as plastic parts, in particular as injection molded parts.

13. Blower according to one of the preceding claims, characterized in that the blades (31) in the direction of rotation of the radial impeller (3) are curved.

14. Blower according to one of the preceding claims, characterized in that the radial distance (d) between a free space (11) facing away from the end of a blade (31) and an inside of the spiral housing (2) in the conveying region of the blower (1) is smaller than 4 mm, in particular 3 mm.