Asymmetric Squeegee for Bidirectional Filter Cleaning

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Solution Overview

Problem

Filter systems in water-carrying household appliances become clogged quickly due to particles, leading to increased filter resistance and reduced volume flow, and existing squeegees cause mechanical wear on the filter surface.

Innovation Solution

A filter system with an asymmetric squeegee that moves in two directions, using different geometries and materials on each side to scrape particles off the filter surface, allowing for effective cleaning while minimizing mechanical stress on the filter.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If a conventional squeegee is used to remove particles from the filter surface, then the filter surface is cleaned effectively, but mechanical wear on the filter surface increases rapidly

Engineering Contradiction:
Improvefilter cleaning effectivenessVSAvoidfilter surface durability
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The doctor blade is designed with asymmetric geometry where the first doctor blade side has a different angle relative to the filter surface than the second doctor blade side. This asymmetry allows one side to be optimized for effective particle removal while the other side applies gentler forces to minimize mechanical wear on the filter surface during bidirectional movement

Inventive Principle:
Principle #4Asymmetry

Solution Approach 2:

The doctor blade is configured to move bidirectionally across the filter surface, alternating between first and second directions of movement. This dynamic approach allows the system to switch between aggressive cleaning mode (when particles accumulate) and gentle maintenance mode (to preserve filter surface), adapting the cleaning intensity to operational needs

Inventive Principle:
Principle #15Dynamics

2Productivity

If the doctor blade exerts strong forces to remove clogged particles, then filter resistance is reduced effectively, but the mechanical stress on the filter surface increases

Engineering Contradiction:
Improvefilter flow efficiencyVSAvoidmechanical stress on filter surface
Core Design Contradiction:
ProductivityVSStress or pressure

Solution Approach 1:

The asymmetric design of the doctor blade creates different contact angles with the filter surface depending on the direction of movement. The first doctor blade side is configured to apply stronger forces for effective particle removal when filter resistance is high, while the second doctor blade side applies reduced forces to minimize mechanical stress during the return stroke or maintenance phase

Inventive Principle:
Principle #4Asymmetry

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 system effectively removes particles from the filter surface, maintaining efficient fluid flow while extending the filter's service life by reducing wear and ensuring reliable operation of household appliances.

Implementation Method 1

the doctor blade with a first doctor blade side and a second doctor blade side... to doctor particles from the filter surface

Methodology Applied
Scientific EffectFriction: Friction

Implementation Method 2

these squeegees often lead to rapid wear of the filter surface due to mechanical abrasion

Methodology Applied
Scientific EffectMechanical abrasion: Abrasion

Data Source

PatentEP4115965B1Filter system and method for cleaning a filter surface
Publication Date: 2024.03.13 BOSCH SIEMENS HAUSGERATE GMBH
  • EP4115965B1 patent drawingFigure 1
  • EP4115965B1 patent drawingFigure 2
  • EP4115965B1 patent drawingFigure 3

AI summary

A filter system (1) for a water-bearing household appliance is provided. The filter system (1) comprises a filter with a filter surface (3) for filtering particles (6) from a fluid, a squeegee (2) with a first squeegee side (4) and a second squeegee side (5), and a squeegee drive configured to move the squeegee (2) across the filter surface (3) in a first direction of movement (v1) and in a second direction of movement (v2) opposite to the first direction of movement (v1) in order to scrape particles (6) from the filter surface (3). The squeegee (2) is configured such that in the first direction of movement (v1), the filter surface (3) first comes into contact with the first squeegee side (4), and in the second direction of movement (v2), it first comes into contact with the second squeegee side (5). Furthermore, the first squeegee side (4) and the second squeegee side (5) have different properties and/or different geometries.Furthermore, a method for cleaning a filter surface (3) of a filter system is provided.