Washing Machine Drum Speed Control for Water-Efficient Tub Cleaning
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Solution Overview
Problem
Conventional drum washing machines face challenges in effectively cleaning the tub's inner circumferential surface due to inefficient water distribution and high water usage, often resulting in reduced cleaning success rates and environmental concerns from chemical detergents used for tub cleaning.
Innovation Solution
A method for controlling a washing machine that involves rotating the drum at specific RPMs to circulate wash water along the tub's inner surface, determining rotational speeds based on the drum's eccentric value, and using minimal water levels to clean the tub without stopping the drum, thereby optimizing water usage and reducing chemical detergent reliance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the drum is rotated at high speed to circulate wash water along the tub's inner circumferential surface, then tub cleaning effectiveness is improved, but water is wasted as it is discharged without being used
Solution Approach 1:
The patent applies preliminary action by rotating the drum at a first rotational speed before supplying wash water to pre-distribute the water along the tub's inner circumferential surface. This ensures the water is properly positioned and utilized for cleaning, preventing waste while maintaining effective tub cleaning.
Solution Approach 2:
The patent maintains continuity of useful action by rotating the drum continuously at different rotational speeds during different phases: first at a first rotational speed to distribute water, then at a second rotational speed for cleaning, and finally at a third rotational speed to prevent water discharge. This continuous operation ensures water is always serving a useful cleaning function.
2Reliability
If detergent is used for tub cleaning, then powerful washing force is achieved, but environmental pollution is caused
Solution Approach 1:
The patent applies self-service by using the wash water itself and the drum's rotation to clean the tub, without requiring additional chemical detergents. The mechanical action of the rotating drum distributing and circulating the wash water provides sufficient cleaning power while avoiding environmental pollution from chemical components.
3Reliability
If the drum is decelerated to 0 RPM or very low rotation speed when eccentric amount exceeds reference, then safety is improved, but tub cleaning success rate is reduced
Solution Approach 1:
The patent applies dynamics by adjusting the drum's rotational speed dynamically based on the detected eccentric amount. When the eccentric amount is within the reference range, the drum rotates at a second rotational speed for effective cleaning. When the eccentric amount exceeds the reference, the drum rotates at a third rotational speed that prevents water discharge while still maintaining some rotation to continue the cleaning process.
Solution Approach 2:
The patent changes the operational parameters by using multiple rotational speeds (first, second, and third rotational speeds) instead of a single fixed speed or complete stop. This allows the system to adapt to different conditions (normal operation vs. high eccentricity) while maintaining tub cleaning functionality and preventing water waste.
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 method enhances tub cleaning efficiency, reduces water waste, and allows for effective cleaning of the tub and surrounding components with a high success rate while minimizing environmental impact.
Implementation Method 1
rotating the drum at a water supply revolutions per minute (RPM), supplying wash water to the tub based on rotating the drum at the water supply RPM, accelerating rotation of the drum based on supplying wash water to the tub
Data Source
AI summary
A method for controlling a washing machine configured to receive laundry and including a tub and a drum located in the tub includes rotating the drum at a water supply revolutions per minute (RPM), supplying wash water to the tub based on rotating the drum at the water supply RPM, accelerating rotation of the drum based on supplying wash water to the tub, sensing a first eccentric value of the drum based on accelerating the rotation of the drum, based on the first eccentric value, determining a rotational speed for rotating the drum, and rotating the drum at the rotational speed.