Washing machine having a self-cleaning drum

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Solution Overview

Problem

Existing washing machines fail to effectively clean the dirt accumulated on the outer and inner walls of the tubs, leading to secondary pollution during the washing process, and existing self-cleaning solutions are either inefficient or require manual installation and cannot reach the bottom areas.

Innovation Solution

A self-cleaning washing machine design with a smooth flange structure at the bottom of the drum and a cover plate over the heating tube chamber, allowing cleaning particles to easily clean the outer and inner tub walls without forming blind corners, preventing dirt accumulation and bacterial breeding, and protecting the heating tube from damage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If cleaning particles are used to clean the outer and inner tub walls, then cleaning effectiveness is improved, but cleaning particles may accumulate in blind corners and complex structures

Engineering Contradiction:
Improvecleaning effectivenessVSAvoidstructure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The invention divides the cleaning space into distinct regions by positioning the flange and its enclosed cavity at the bottom of the drum, separating the cleaning particle circulation area from the heating tube chamber. This segmentation prevents cleaning particles from accumulating in blind corners while maintaining effective cleaning coverage on the tub walls.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The heating tube chamber is extracted and isolated from the main cleaning space by enclosing it within the flange structure. This extraction removes the heating tube area from the cleaning particle circulation path, preventing particle accumulation in the heating tube chamber while preserving the cleaning function in the outer tub space.

Inventive Principle:
Principle #2Taking out (Extraction)

2Strength

If a flange with complex structure is used to support the drum, then structural strength is improved, but it creates blind corners that trap dirt and damage cleaning particles

Engineering Contradiction:
Improvestructural strengthVSAvoiddirt accumulation
Core Design Contradiction:
StrengthVSObject-generated harmful factors

Solution Approach 1:

The invention applies different surface qualities to different regions: the flange enclosed cavity and heating tube chamber have smooth surfaces that prevent dirt adhesion, while the outer tub walls maintain the texture needed for effective cleaning. This local differentiation resolves the conflict between structural strength and dirt accumulation prevention.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The flange structure, which originally created harmful blind corners for dirt accumulation, is transformed into a beneficial enclosed cavity that directs cleaning particles along smooth surfaces. The cavity converts the potential harm of structural complexity into a benefit by channeling cleaning particles effectively while preventing dirt trapping.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

3Reliability

If cleaning particles are allowed to circulate freely between drum and outer tub, then cleaning coverage is improved, but particles may enter the heating tube chamber and cause damage

Engineering Contradiction:
Improvecleaning coverageVSAvoidheating tube damage
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The flange enclosed cavity acts as an intermediary structure that mediates between the cleaning particle circulation space and the heating tube chamber. It allows cleaning particles to effectively clean the outer tub walls while serving as a protective barrier that prevents particles from entering and damaging the heating tube.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The heating tube chamber is extracted and isolated from the cleaning particle circulation path by enclosing it within the flange structure. This extraction removes the heating tube from potential contact with cleaning particles while maintaining the cleaning function in the outer tub space.

Inventive Principle:
Principle #2Taking out (Extraction)

4Device complexity

If manual installation and removal of cleaning devices is required, then device simplicity is improved, but ease of operation deteriorates

Engineering Contradiction:
Improvedevice simplicityVSAvoidease of operation
Core Design Contradiction:
Device complexityVSEase of operation

Solution Approach 1:

The washing machine cleaning system is designed to be self-sufficient, with the drum rotation automatically driving the cleaning particles to clean both the outer and inner tub walls. The system requires no manual installation or removal of cleaning devices, as the cleaning action is automatically generated by the drum's rotation and the cleaning particles' circulation.

Inventive Principle:
Principle #25Self-service

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 smooth structure facilitates thorough cleaning of the tub surfaces, preventing secondary contamination and ensuring the heating tube is protected from damage, while maintaining easy operation without the need for manual disassembly.

Implementation Method 1

The heating tube heats the washing water in order to increase the activity of enzyme containing detergent and to increase the cleaning ratio

Methodology Applied
Scientific EffectHeating: Heating

Implementation Method 2

the cleaning particles move in water, rub and collide against the outer wall of the drum and the inner wall of the outer tub

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP3202967B1Washing machine having a self-cleaning drum
Publication Date: 2020.04.08 QINGDAO HAIER DRUM WASHING MACHINE CO LTD
  • EP3202967B1 patent drawingFigure 1
  • EP3202967B1 patent drawingFigure 2
  • EP3202967B1 patent drawingFigure 3

AI summary

A self-cleaning drum washing machine, at least comprises a drum (1) and an outer tub (9) which are coaxially arranged. Cleaning particles (23) are arranged between the drum (1) and the outer tub (9). Structures between the drum (1) and the outer tub (9) opposite to each other are a smooth structure. A flange is arranged at the bottom of the drum (1); the flange (2) is fixedly connected to the drum; the outer portion of the flange (2) has a smooth structure or an enclosed cavity is arranged on the outer portion of the drum bottom; the flange (2) is arranged in the cavity; a shaft hole (4) is arranged at the center of the cavity; and a drum shaft (3) sticks into the cavity through the shaft hole (4) and is connected to the flange (2). The portions between the drum and the outer tub have the smooth structures which go against the attachment of dirt, so that the outer wall of the drum (1) and the inner wall of the outer tub (9) can be conveniently cleaned by the cleaning particles.