Movable Pump Filter Assembly for Washing Machine Self-Cleaning

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Solution Overview

Problem

In household appliances like washing machines and dishwashers, the filter in the recirculation circuit often clogs due to impurity accumulation, requiring frequent maintenance that is difficult because the filter is inaccessible, leading to reduced service life and inefficiency in the recirculation process.

Innovation Solution

A pump assembly with a filter that can move between two positions, allowing fluid flow for filtration and cleaning, enabling efficient filtering and maintenance without external access, thereby extending the filter's service life and improving recirculation efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the filter is made fixed on the intake side of the recirculation pump, then the filter can effectively capture impurities, but the filter becomes inaccessible for cleaning and maintenance

Engineering Contradiction:
Improvefilter effectivenessVSAvoidfilter accessibility
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The filter is designed to be movable rather than fixed, allowing it to switch between a first stable position for filtration and a second stable position for cleaning. This dynamic positioning resolves the contradiction by enabling both effective filtration when in the first position and accessibility for maintenance when in the second position.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The filter assembly is segmented into movable and stationary components, with the filter cartridge able to independently change position relative to the pump housing. This segmentation allows the filter to be separated from its filtration position to access the cleaning position, solving the accessibility problem while maintaining filtration effectiveness.

Inventive Principle:
Principle #1Segmentation

2Ease of operation

If the filter is positioned to be easily accessible from outside, then maintenance becomes simple, but the filter cannot effectively protect the recirculation pump

Engineering Contradiction:
Improvefilter accessibilityVSAvoidpump protection
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The filter's ability to dynamically reposition between filtration and cleaning positions allows it to fulfill both protective and maintainable functions. When in the first stable position, it effectively protects the pump; when in the second position, it becomes accessible for cleaning without compromising long-term protection capability.

Inventive Principle:
Principle #15Dynamics

3Productivity

If the filter remains in one position for continuous filtration, then the recirculation process is efficient, but impurity accumulation clogs the filter quickly

Engineering Contradiction:
Improverecirculation efficiencyVSAvoidfilter service life
Core Design Contradiction:
ProductivityVSDuration of action of stationary object

Solution Approach 1:

The filter operates in periodic cycles, alternating between filtration mode (first stable position) and cleaning mode (second stable position). This periodic action prevents continuous impurity accumulation by periodically removing captured particles, thereby extending filter service life while maintaining recirculation efficiency during filtration phases.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The filter is designed to clean itself by moving to the second stable position where wash liquid flows through it in reverse or at an angle to remove accumulated impurities. This self-service capability extends the filter's service life without requiring external intervention, maintaining productivity while preventing clogging.

Inventive Principle:
Principle #25Self-service

4Duration of action of stationary object

If the filter is cleaned frequently to prevent clogging, then the filter service life is extended, but the appliance requires more maintenance time and operational interruptions

Engineering Contradiction:
Improvefilter service lifeVSAvoidmaintenance time
Core Design Contradiction:
Duration of action of stationary objectVSLoss of time

Solution Approach 1:

The filter cleans itself automatically by repositioning to the second stable position and utilizing wash liquid flow to remove impurities. This self-service mechanism extends filter service life without requiring manual intervention or operational interruptions, thereby eliminating maintenance time loss while extending service life.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The cleaning operation is integrated into the normal operational cycle rather than requiring separate maintenance interruptions. The filter can be cleaned in-situ during appliance operation by switching positions, maintaining continuous useful action without time loss to external maintenance activities.

Inventive Principle:
Principle #20Continuity of useful 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

The filter's ability to change positions facilitates effective cleaning and maintenance, enhancing the service life of the filter and the appliance, ensuring a more reliable and efficient recirculation process.

Implementation Method 1

a filter (9) capable of moving, under the action of gravity or an actuating device, between at least two stable positions

Methodology Applied
Scientific EffectGravity: Gravitation

Data Source

PatentEP2654545B1Pump assembly with movable filter for washing machines
Publication Date: 2016.06.15 WHIRLPOOL EMEA SPA
  • EP2654545B1 patent drawingFigure 1
  • EP2654545B1 patent drawingFigure 2
  • EP2654545B1 patent drawingFigure 3~4

AI summary

A pump assembly (1,1') for household appliances such as washing machines and the like, comprising at least one pump (3, 4, 3', 4'), a body (2,2') and a filter (9,9'), wherein the filter (9,9') can be positioned by means of an actuator (6) in at least two stable positions comprising a first position, in which said filter (9,9') filters a wash liquid flow, and a second position, in which said filter (9,9') is cleaned by a liquid flow running in the opposite direction with respect to said wash liquid flow.