Laundry Drum Shell Structure for Gentle Mechanical Washing

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Solution Overview

Problem

Existing laundry drums face challenges in mechanical treatment effectiveness while minimizing mechanical stress on laundry, maintaining structural stability, and reducing acoustic vibrations, with previous designs either being too harsh or lacking sufficient liquid exchange.

Innovation Solution

A laundry drum with a sheet metal shell featuring linear elevations in the circumferential direction, extending helically, and flood holes in cylindrical areas, which stabilize the drum, reduce material usage, and enhance mechanical washing efficiency without causing acoustic vibrations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If carriers are used for mechanical laundry treatment, then mechanical treatment effectiveness is improved, but mechanical stress on laundry increases

Engineering Contradiction:
Improvemechanical treatment effectivenessVSAvoidmechanical stress on laundry
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The patent replaces the traditional mechanical carrier system with a drum shell surface structure featuring linear elevations and cylindrical areas. The elevated linear structures create relative movement between laundry items and the drum surface, providing mechanical treatment through the drum shell itself rather than separate carriers. This substitution eliminates the need for additional mechanical elements that could damage laundry while maintaining washing effectiveness through the engineered surface geometry.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Loss of substance

If drum shell material is reduced to minimum, then material usage and cost are improved, but structural stability deteriorates

Engineering Contradiction:
Improvematerial usageVSAvoidstructural stability
Core Design Contradiction:
Loss of substanceVSStability of the object's composition

Solution Approach 1:

The patent employs a thin-walled drum shell with integrated linear elevations and cylindrical areas that provide structural reinforcement without requiring thick material. The elevated linear structures act as stiffening elements within the thin shell, distributing stresses and maintaining structural integrity. This allows the drum to achieve necessary structural stability with minimal material thickness, reducing both material usage and cost while preventing acoustic vibrations.

Inventive Principle:
Principle #30Flexible shells and thin films

Solution Approach 2:

The patent incorporates curved cylindrical areas and elevated linear structures with specific radii of curvature into the drum shell. These curved geometric features enhance the structural stability of the thin-walled drum by distributing mechanical stresses more evenly throughout the shell. The curvature provides inherent structural reinforcement, allowing the use of minimal material thickness while maintaining drum integrity and reducing vibration tendencies.

Inventive Principle:
Principle #14Spheroidality (Curvature)

3Quantity of substance

If flood holes are arranged in wave troughs and wave crests, then liquid exchange is improved, but risk to laundry increases

Engineering Contradiction:
Improveliquid exchangeVSAvoidrisk to laundry
Core Design Contradiction:
Quantity of substanceVSObject-affected harmful factors

Solution Approach 1:

The patent strategically positions flood holes within specific cylindrical areas and along elevated linear structures rather than uniformly across the drum shell. This localized arrangement optimizes liquid exchange at critical locations where water needs to penetrate or drain, while avoiding areas where high-velocity water flow could damage laundry. The selective placement of flood holes in the engineered surface geometry provides effective liquid exchange while minimizing harmful effects on the laundry.

Inventive Principle:
Principle #3Local quality

Data Source

PatentEP2245224B1Drum for a laundry treatment machine
Publication Date: 2016.05.25 BSH HAUSGERATE GMBH
  • EP2245224B1 patent drawingFigure 1
  • EP2245224B1 patent drawingFigure 2~4
  • EP2245224B1 patent drawingFigure 5~6

AI summary

The aim of the invention is to provide a drum (3) the jacket structure of which has the advantageous properties of prior art structures (6) that are distributed in the peripheral direction (40), said structures rising from the cylindrical shape of the drum jacket (4) mounted in the drum, and yet allow influence on the mechanical laundry treatment during the rotational movement of the drum (3). The drum according to the invention is characterized in that the structures are formed from linear elevations (6) that extend at a right angle to the perimeter (40).