EP4624651A1

EP4624651A1 - Assembly for an appliance with a tilted fan wheel

Info

Publication number: EP4624651A1
Application number: EP24166617.1A
Authority: EP
Inventors: Adam Zarzycki; Alexander Drebant; Andrea LOHRMANN
Original assignee: BSH Hausgeraete GmbH
Current assignee: BSH Hausgeraete GmbH
Priority date: 2024-03-27
Filing date: 2024-03-27
Publication date: 2025-10-01
Also published as: CN120720244A

Abstract

The present invention relates to an assembly (10) for an appliance (100), comprising a process air channel (11) and a fan wheel (20) arranged at least partially inside the process air channel, wherein the fan wheel is driven by a shaft (21) defining a rotation axis of the fan wheel (20), wherein the process air channel comprises an inlet flow part arranged upstream the fan wheel and an outlet flow part arranged downstream the fan wheel, wherein the outlet flow part of the process air channel is orientated perpendicular to the rotation axis and is configured to guide process air flow generated by the fan wheel (20) into a drum (110), wherein the fan wheel and the outlet flow part of the process air channel are tilted with regard to a horizontal axis. Furthermore, the present invention relates to a household appliance (100) with an assembly.

Description

The present invention relates to an assembly for an appliance, comprising a process air channel and a fan wheel arranged at least partially inside the process air channel, wherein the fan wheel is driven by a shaft defining a rotation axis of the fan wheel, wherein the process air channel comprises an inlet flow part arranged upstream the fan wheel and an outlet flow part arranged downstream the fan wheel. Furthermore, the present invention relates to an appliance with the said assembly.
Tumble dryers are usually equipped with fan wheels in order to move heated process air to the drum and to remove humid air from the drum. The humidity filled air from the drum is regularly guided through heat exchanger for drying the process air by condensation and re-heating. The fan wheel is made of plastic or metal and is driven by an electric motor for creating the main air flow in the appliance. The efficiency of the fan wheel is a characteristic feature, which describes how much of the electrical energy consumption of the motor is converter into hydraulic energy of the process air by the fan wheel. In order to use the fan wheel in a most efficient way it is required to connect the fan wheel to an optimized air duct system.
The so called air nozzle of the process air channel guides the air flow towards the fan wheel. The air nozzle usually connects a heating element or a corresponding heat exchanger with the fan wheel and is arranged with the fan wheel in the bottom group or bottom module of the appliance. Additionally to these inlet flow conditions defined by the air nozzle, the outlet flow conditions of the process air channels also affect the fan wheel efficiency. In particular, the orientation of the fan wheel axis has an influence on the flow conditions.
Usually, in appliances a radially acting fan wheel is utilized. Thus, the inlet flow is guided axially to the fan wheel and the outlet flow is guided radially away from the fan wheel. The relative angle between the inlet flow part and the outlet flow part of the process air channel is regularly 90°. Also the transition between the outlet flow part of the process air channel and the drum usually comprises an angle of 90°. Such sharp angles are prone to cause vortex generation and recirculation areas within the process air channel.
It is therefore an object of the present invention to provide an assembly and an appliance with improved efficiency. This problem is solved by an assembly according to claim 1 and by an appliance according to the features of claim 9. Advantageous embodiments are set out in the dependent claims.
According to one aspect of the present invention, an assembly for an appliance is provided. The assembly comprises a process air channel and a fan wheel that is arranged at least partially inside the process air channel. The fan wheel may be formed as a radially acting or an axially acting fan wheel in terms of the outflow direction of the fan wheel.
The fan wheel is driven by a shaft defining a rotation axis of the fan wheel. The process air channel comprises an inlet flow part arranged upstream the fan wheel and an outlet flow part arranged downstream the fan wheel. The terms "upstream" and "downstream" may refer to a direction of the air flow inside the process air channel which is caused by the fan wheel.
The outlet flow part of the process air channel is orientated perpendicular to the rotation axis and is configured to guide process air flow generated by the fan wheel into a treatment space, wherein the fan wheel and at least partially the outlet flow part of the process air channel are tilted with regard to a horizontal axis.
The outlet flow part of the process air channel may be formed as a diffusor of the appliance. The inlet flow part of the process air channel may be formed as an air nozzle for the fan wheel.
In a further aspect of the invention an appliance, especially formed as a home appliance, is provided. The appliance comprises the inventive assembly. For example the appliance may be formed as tumble dyer, washer dryer, steam cooker, steam treatment device, dishwasher. In particular, the appliance may comprise a process air channel for guiding an air flow. The process air channel may be formed as a loop or may be formed opened in order to provide an air flow or any gas flow, e.g. steam, warm air, cool air and the like, to a treatment space. Such treatment space may be formed as a drum or a washing area or a cooking area.
By tilting the fan wheel, the flow direction may be aligned with the air guiding geometries of the process air channel. Thereby, the efficiency of the fan wheel may be increased and the same airflow value may be provided with a lower electrical power input of the motor that drives the fan wheel. With such optimized flow conditions, the fan wheel operates at a lower torque for the same airflow value. Therefore, the power input of the fan drive is reduced.
Moreover, the lower rotation speed of fan wheel may result in a positive effect on noise and vibration of the appliance.
In an embodiment, the fan wheel and the outlet flow part of the process air channel are tilted by a positive angle or a negative angle with regard to the horizontal axis. Thus, the tilting of the fan wheel can be adjusted based on a given design and the overall measurements of the appliance. Especially, tilting of the fan wheel rotation axis by a positive angle may result the outflow of the fan wheel pointing to the treatment space. Tilting of the fan wheel rotation axis by a negative angle may result in the outflow of the fan wheel pointing away from the treatment space.
In a further embodiment, the outlet flow part of the process air channel comprises an inlet with the arranged fan wheel and an outlet for connecting the treatment space. The inlet of the outlet flow part is pointing away from the treatment space and is interconnected with the outlet by a bent or curved section. Such configuration is provided by a negative angle between the horizontal axis and the fan wheel rotation axis.
The outflow of the fan wheel is guided by a bended or curved outlet flow part into the treatment space. Thus, the pressure resistance of the diffuser is reduced, in particular by providing a geometry which facilitates steady and laminar flow conditions.
The horizontal axis may be defined as an axis parallel to the base or ground of the appliance. In particular, the horizontal axis may extend perpendicular to a vertical axis which may be defined by a gravity vector of the gravity acting on the appliance.
Based on a further embodiment, the outlet flow part of the process air channel comprises an inlet with the arranged fan wheel and an outlet for connecting the treatment space. The inlet of the outlet flow part is pointing to the treatment space and is interconnected with the outlet by a straight section. By providing these measures a positive angle between the horizontal axis and the fan wheel rotation axis is realized. These measures may result in a straight or in a more straightened geometry of the outlet flow part of the process air channel. Thus, the pressure resistance of the diffuser is reduced by avoiding any vortex generation.
In a further embodiment, an orientation of the inlet of the outlet flow part is aligned with an axial or radial outflow direction of the fan wheel. The outlet flow of the fan wheel is aligned with the air duct orientation of the outlet flow part of the process air channel. Thus, the change in flow direction at the beginning of the diffusor is less abrupt. This provides uniform outflow conditions for the fan wheel and avoids recirculation areas.
The lower pressure resistance of the outlet flow part of the process air channel may result in the possibility to set the rotation speed of the fan wheel to a lower value while maintaining the same airflow value. The power input of the fan drive is therefore reduced as well as noise emission and vibration from the rotating components.
Based on a further embodiment, the assembly comprises a motor which is configured to drive the fan wheel and/or a treatment space formed as a drum, wherein the motor is arranged parallel to the horizontal axis. Thus, the motor may be utilized solely for the purpose of driving the fan wheel or to drive the drum or any other movable treatment space and the fan wheel simultaneously. The direct driving of the fan wheel by the motor may result in an attachment of the motor in a similar tilted manner as the fan wheel.
The motor may be formed as an electric motor formed with brushes or formed as a brushless motor. The motor may be positioned at a side of the fan wheel pointing away from the treatment space or pointing in direction of the treatment space.
In a further embodiment, the fan wheel and the motor are connected by a flexible shaft, a coupling, a cardan shaft and/or a gear. Thus, the motor may remain in an orientation perpendicular or parallel to the horizontal axis while the fan wheel is kept tilted compared to the motor. Such flexible coupling between the motor and the fan wheel also allows driving of the fan wheel by a so called drum motor which drives the drum of the appliance.
Based on a further embodiment, the inlet flow part extends parallel to the horizontal axis and ends in the inlet of the outlet flow part, wherein the inlet flow part ends by a bended section that points towards the rotation axis of the fan wheel. This measure may result in a more straight inflow condition of the fan wheel which also may improve the efficiency of the fan wheel.
The invention describes a device with a separate electric motor for the fan wheel. However, the invention can also be applied to a dryer with a belt drive for the fan wheel, and to a series device. A flexible shaft, a coupling, a cardan shaft or other solutions could realize the bending angle needed for tilting the fan.
The advantages and features explained above in connection with the device also apply analogously to the method and vice versa. Individual features or aspects of the present invention can be combined with each other and have the advantages explained in this context.
In the following, the invention is explained in detail by means of advantageous embodiments with reference to the attached figures. The figures show:

Fig. 1: a schematic cross section of a household appliance with an assembly according to one embodiment.
Fig. 2: a schematic cross section of a household appliance with an assembly according to another embodiment.

In the figures, identical or corresponding elements are labelled with the same reference signs. Values and characteristics such as numerical values, shapes, components, positions of components and the way in which the components are connected to each other are merely illustrative and not restrictive. For reasons of clarity and to improve recognisa-bility, different scales are sometimes used in the drawings.
Fig. 1 shows a schematic cross section of a household appliance 100 with an assembly 10 according to one embodiment. In the shown example, the appliance 100 is formed as a tumble dyer. The heat exchangers of the appliance 100 are not shown for improved visibility of the components of the assembly 10.
The assembly 10 comprises a process air channel 11 and a fan wheel 20 that is arranged inside the process air channel 11. The fan wheel 20 is formed as a radially acting fan wheel in terms of the outflow direction of the fan wheel 20.
The fan wheel 20 is driven by a shaft 21 defining a rotation axis R of the fan wheel 20. The process air channel 11 comprises an inlet flow part 12 arranged upstream the fan wheel 20 and an outlet flow part 13 arranged downstream the fan wheel 20. The fan wheel sucks the process air via the inlet flow part 12 and pushes the process air away into the outlet flow part 13. In the shown example, the fan wheel 20 is driven by an electric motor 22 which is directly attached to the fan wheel 20. The rotation axis R schematically illustrates the orientation of the shaft 21 of the fan wheel 20 which may also be the shaft of the motor 22.
The outlet flow part 13 of the process air channel 11 may be formed as a diffusor of the appliance 100. The inlet flow part 12 of the process air channel 11 may be formed as an air nozzle for the fan wheel 20.
The appliance 100 further comprises a treatment space 110. The treatment space 110 is exemplary formed as a drum 110 for drying or treating laundry or other textiles. The treatment space 110 may also form a part of the process air channel 11. The process air channel 11 is formed as a loop in order to provide an air flow to the drum 110.
The outlet flow part 13 of the process air channel 11 is orientated perpendicular to the rotation axis R and is configured to guide a flow of the air generated by the fan wheel 20 into the drum 110. The fan wheel 20 and the outlet flow part 13 of the process air channel 11 are tilted with regard to a horizontal axis H.
The horizontal axis H is defined as an axis parallel to the base 120 or ground of the appliance 100.
The outlet flow part 13 of the process air channel 11 comprises an inlet 14 with the arranged fan wheel 20 and an outlet 15 which is connected to the treatment space 110.
In the shown embodiment, the fan wheel 20 and the outlet flow part 13 of the process air channel 11 are tilted by a negative angle -β with regard to the horizontal axis H. The inlet 14 of the outlet flow part 13 is pointing away from the treatment space 110 and is interconnected with the outlet 15 by a bent or curved section 16. The outflow of the fan wheel 20 is guided by the bended or curved section 16 into the treatment space 110 with reduced resistance.
Based on an alternative embodiment, the fan wheel 20 may be directly or indirectly driven by a drum motor 23 of the appliance 100. The drum motor 23 may be utilized in order to rotate the drum 110. The linkage 24 between the drum motor 23 and the fan wheel 20 may be provided by a flexible coupling like a cardan, a flexible axis, a gear and the like. Such linkage 24 would also allow the arrangement of the electric motor 22 without any tilting, since the tilted fan wheel 20 or the shaft 21 of the fan wheel 20 can be connected to the motor 22 via the flexible linkage 24, too.
In Fig. 2 a further cross section of a household appliance 100 with an assembly 10 according to another embodiment is illustrated. In contrast to the first embodiment, here the fan wheel 20 and the outlet flow part 13 of the process air channel 11 are tilted by a positive angle +β with regard to the horizontal axis H. Thus, the fan wheel 20 is positioned further backwards the appliance 100 in order to allow a more straight outlet flow part with connecting angles between the outlet 15 and the treatment space 110 of larger than 90°.

List of reference signs

100 - household appliance
110 - treatment space
120 - base of appliance
10 - assembly
11 - process air channel
12 - inlet flow part
13 - outlet flow part
14 - inlet of outlet flow part
15 - outlet of outlet flow part
16 - curved section
20 - fan wheel
21 - shaft
22 - motor
23 - drum motor
24 - flexible linkage
H - horizontal axis
R - rotation axis of fan wheel

Claims

Assembly (10) for an appliance (100), comprising a process air channel (11) and a fan wheel (20) arranged at least partially inside the process air channel (11), wherein the fan wheel (20) is driven by a shaft (21) defining a rotation axis (R) of the fan wheel (20), wherein the process air channel (11) comprises an inlet flow part (12) arranged upstream the fan wheel (20) and an outlet flow part (13) arranged downstream the fan wheel (20), wherein the outlet flow part (13) of the process air channel (11) is orientated at least partially perpendicular to the rotation axis (R) and is configured to guide process air flow generated by the fan wheel (20) into a treatment space (110), characterized in that the fan wheel (20) and at least partially the the outlet flow part (13) of the process air channel (11) are tilted with regard to a horizontal axis (H).
Assembly of claim 1, wherein the fan wheel (20) and the outlet flow part (13) of the process air channel (11) are tilted by a positive angle (+β) or a negative angle (-β) with regard to the horizontal axis (H).
Assembly of claim 1 or 2, wherein the outlet flow part (13) of the process air channel (11) comprises an inlet (14) with the arranged fan wheel (20) and an outlet (15) for connecting the treatment space (110), wherein the inlet (14) of the outlet flow part (13) is pointing away from the treatment space (110) and is interconnected with the outlet (15) by a bent or curved section (16).
Assembly of any one of the claims 1 to 3, wherein the outlet flow part (13) of the process air channel (11) comprises an inlet (14) with the arranged fan wheel (20) and an outlet (15) for connecting the treatment space (110), wherein the inlet (14) of the outlet flow part (13) is pointing to the treatment space (110) and is interconnected with the outlet (15) by a straight section.
Assembly of any one of the claims 1 to 4, wherein an orientation of the inlet (24) of the outlet flow part (13) is aligned with an axial or radial outflow direction of the fan wheel (20)
Assembly of any one of the claims 1 to 5, wherein the assembly (10) comprises a motor (21, 23) which is configured to drive the fan wheel (20) and/or a treatment space (110) formed as a drum, wherein the motor (21, 23) is arranged parallel to the horizontal axis (H).
Assembly of claim 7, wherein the fan wheel (20) and the motor (22) are connected by a flexible linkage (24).
Assembly of any one of the claims 1 to 7, wherein the inlet flow part (12) extends parallel to the horizontal axis (H) and ends in the inlet (14) of the outlet flow part (13), wherein the inlet flow part (12) ends by a bended section that points towards the rotation axis (R) of the fan wheel (20).
Appliance (100), comprising an assembly (10) of anyone of the previous claims.