Washing Drum Rotation Control for Low-Vibration Moisture Removal
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional washing machines experience increased noise and vibration during the dehydration cycle due to high-speed drum rotation, which complicates efficient moisture removal from laundry.
Innovation Solution
A control method for a washing machine that involves multiple stages of drum rotation, including first-stage rotation at a predetermined speed, second-stage rotation at a specific target RPM, deceleration rotation with lower speed and iterative pauses, and third-stage rotation at a higher RPM, along with the supply of hot air to facilitate moisture removal.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the drum is rotated at the highest speed during the dehydration cycle to remove moisture efficiently, then the moisture removal efficiency is improved, but the noise and vibration increase
Solution Approach 1:
The dehydration cycle is segmented into multiple stages with different rotational speeds. The drum rotates at high speed during second-stage rotation for moisture removal, then decelerates during deceleration rotation to reduce noise and vibration, and finally accelerates again during third-stage rotation. This segmentation allows the system to achieve both high productivity and reduced harmful factors at different time points.
Solution Approach 2:
The drum rotation follows a periodic pattern of acceleration and deceleration across three stages. The rotational speed varies periodically: first-stage rotation at predetermined speed, second-stage rotation at high target RPM for moisture removal, deceleration rotation at lower speed to reduce noise and vibration, and third-stage rotation at second target RPM. This periodic action enables the system to balance productivity with noise and vibration control.
2Productivity
If the drum rotates at high speed continuously to maximize dehydration performance, then the moisture removal efficiency is improved, but the laundry becomes tangled and drying performance decreases
Solution Approach 1:
The drum rotation is designed with periodic acceleration and deceleration phases. During second-stage rotation, the drum rotates at high speed to remove moisture efficiently. During deceleration rotation, the speed is reduced to allow laundry to redistribute uniformly. This periodic action prevents continuous high-speed rotation from causing laundry tangling while maintaining dehydration performance.
Solution Approach 2:
The deceleration rotation stage is inserted before the third-stage rotation to preliminarily redistribute the laundry. By reducing speed during deceleration rotation, the laundry has time to untangle and redistribute uniformly before the next acceleration phase, ensuring optimal conditions for the subsequent high-speed rotation.
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 effectively reduces noise and vibration while improving the efficiency of moisture removal from laundry by disentangling and uniformly dispersing laundry, thereby enhancing drying performance.
Implementation Method 1
supplying hot air into the drum via a heater
Implementation Method 2
facilitate moisture removal from laundry
Data Source
AI summary
Disclosed is a control method of a washing machine. The method includes performing first-stage rotation in which a drum is rotated at a predetermined rotational speed, performing second-stage rotation in which the drum is rotated at a first target RPM when a predetermined time has passed after the first-stage rotation ends, performing deceleration rotation in which the rotational speed of the drum is kept at a lower value than in the second-stage rotation, and performing third-stage rotation in which the drum is rotated at a second target RPM that is greater than the rotational speed of the drum in the deceleration rotation. Accordingly, it is possible to prevent laundry from being adhered to an inner surface of the drum during removal of moisture contained in laundry, and to achieve an increased contact area between laundry and hot air via uniform dispersion of laundry, resulting in enhanced laundry drying performance.