Laundry Drum Pump Synchronization for Efficient Liquid Distribution

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Solution Overview

Problem

Conventional laundry care devices fail to synchronize the circulating process with the rotation of the laundry drum, leading to inefficient washing liquid distribution, where liquid either ricochets off the laundry or flows outside the drum, resulting in poor soaking.

Innovation Solution

A laundry care appliance with a controller that activates the pumping device at the beginning of the rotation process and deactivates it at the end, ensuring effective coupling between drum rotation and liquid pumping, along with alternating rotation directions and controlled rotation speeds to optimize wetting and liquid circulation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the pumping device operates continuously regardless of drum rotation, then washing liquid is constantly supplied to the laundry, but the washing liquid ricochets off the laundry or flows outside the drum when the drum is stationary, resulting in poor soaking efficiency

Engineering Contradiction:
Improvewashing liquid distribution efficiencyVSAvoidsoaking effectiveness
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The controller activates the pumping device only after detecting that the laundry drum has reached a predetermined rotational speed. This preliminary condition ensures that the drum is already rotating when washing liquid is supplied, preventing the liquid from ricocheting off stationary laundry or flowing outside the drum, thereby ensuring effective soaking from the start

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system uses a sensor to detect the rotational speed of the laundry drum and provides feedback to the controller. The controller continuously monitors this feedback and adjusts the pumping device operation accordingly - activating the pump only when the drum reaches the required speed and deactivating it when the speed drops below the threshold, ensuring synchronized operation and maintaining optimal soaking conditions

Inventive Principle:
Principle #23Feedback

2Reliability

If the pumping device is activated only when the drum rotates, then washing liquid is effectively distributed through the rotating laundry, but the pumping operation becomes dependent on drum speed variations, potentially reducing consistent liquid circulation

Engineering Contradiction:
Improvewashing liquid distribution effectivenessVSAvoidliquid circulation consistency
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The system dynamically adjusts the pumping device operation based on real-time drum rotation speed. Rather than using a fixed timing schedule, the controller continuously adapts pump activation and deactivation to the actual rotational conditions of the drum, ensuring that pumping occurs only when mechanically effective while maintaining consistent liquid circulation through responsive control

Inventive Principle:
Principle #15Dynamics

3Productivity

If the pumping device operates at high speed continuously, then washing liquid is rapidly circulated through the laundry, but energy consumption increases and the pumping device may not have sufficient time to refill from the tub, reducing available washing liquid

Engineering Contradiction:
Improvewashing liquid circulation rateVSAvoidpumping device energy consumption
Core Design Contradiction:
ProductivityVSUse of energy by moving object

Solution Approach 1:

The pumping device operates in periodic cycles rather than continuously. The controller activates the pump at high speed only during periods when the drum rotation ensures effective liquid distribution, then deactivates it to allow the tub to refill with washing liquid. This periodic operation maintains high circulation rates when needed while providing recovery periods for liquid replenishment, optimizing both productivity and energy efficiency

Inventive Principle:
Principle #19Periodic action

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This approach ensures efficient and reproducible pumping, thorough wetting of laundry, and optimal washing performance by synchronizing liquid circulation with drum rotation, preventing liquid from flowing outside and ensuring consistent washing results.

Implementation Method 1

a pumping device for pumping washing liquid being arranged in the line, the pumping device being designed to pump washing liquid out of the tub through the drain opening

Methodology Applied
Scientific EffectPumping: Pump

Implementation Method 2

the washing liquid conveyed into the laundry drum can be entrained by the rotating laundry drum

Methodology Applied
Scientific EffectEntrainment: Entrainment

Data Source

PatentEP3481985B1Laundry treating apparatus with a controller
Publication Date: 2020.08.05 BSH HAUSGERATE GMBH
  • EP3481985B1 patent drawingFigure 1
  • EP3481985B1 patent drawingFigure 2
  • EP3481985B1 patent drawingFigure 3

AI summary

The present invention relates to a laundry care appliance (100), comprising an outer tub (105) for receiving washing liquid, wherein an inner tub (107) for receiving laundry is arranged in the outer tub (105), wherein the outer tub (105) has a discharge opening (115) and an inlet nozzle (117), wherein the discharge opening (115) is fluidically connected with the inlet nozzle (117) via a line (119), wherein a pumping device (121) for pumping washing liquid is arranged in the line (119), wherein the pumping device (121) is designed to pump washing liquid through the discharge opening (115) out of the outer tub (105) and to pump the discharged washing liquid through the line (119) and through the inlet nozzle (117) again into the inner tub (107) arranged in the outer tub (105) in order to wet again the laundry in the inner tub (107) with washing liquid; a drum drive (111) for rotating the inner tub (107); and a controller (123) for controlling the drum drive (111) and the pumping device (121). The controller (123) is designed to control the drum drive (111) during a rotation operation (145) in order to rotate the inner tub (107) with a rotational speed (147). The controller (123) is designed to activate the pumping device (121) at the start of the rotation operation (145) in order to pump washing liquid through the discharge opening (115) out of the outer tub (105) into the line (119) and to again supply the discharged washing liquid through the line (119) and through the inlet nozzle (117) to the laundry in the inner tub (107). The controller (123) is designed to deactivate the pumping device (121) at the end of the rotation operation (145).