Laundry Machine Drum Speed Control to Reduce Spin-Cycle Vibration
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Solution Overview
Problem
Laundry machines experience excessive noise and vibration during the spinning cycle due to unbalanced drum rotation, which existing control methods fail to adequately address.
Innovation Solution
A control method for a laundry machine that includes a balancer system, which decreases the drum speed when vibration exceeds a predetermined value, maintains a constant speed for balancing, and uses a suspension assembly to separate the drum's vibration from the tub's, employing a rear gasket for sealing and a flexible supporting structure to reduce noise and vibration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the drum rotates at high speed during the spinning cycle, then the spinning efficiency is improved, but excessive noise and vibration are generated
Solution Approach 1:
The control method performs preliminary actions by rotating the drum at a first rotation speed before reaching the final high spinning speed, and by controlling the rotation speed to pass through a transient region where vibration occurs. This preliminary speed control prevents excessive vibration from occurring in the first place, allowing the drum to eventually reach high spinning speeds efficiently while minimizing noise and vibration generation throughout the process.
2Speed
If the drum rotation speed is increased to improve spinning performance, then the spinning cycle efficiency is improved, but drum vibration increases
Solution Approach 1:
The control method dynamically adjusts the drum rotation speed throughout the spinning cycle rather than maintaining a constant high speed. The rotation speed is controlled to pass through the transient region at a limited speed to minimize vibration, then increased to a second rotation speed after the transient region. This dynamic speed control allows the drum to achieve high spinning speeds for efficient water removal while maintaining stability by avoiding excessive vibration during critical transition phases.
3Stability of the object's composition
If the drum is supported rigidly to reduce vibration, then the drum stability is improved, but the tub vibration cannot be separated from drum vibration
Solution Approach 1:
The support system is segmented into multiple independent elements: elastic elements (springs) that support the drum independently from the tub, and a separate shock absorber element. This segmentation allows the drum to be isolated from the tub structurally, so that drum vibration does not directly transmit to the tub. The elastic elements provide flexible support that reduces vibration transmission, while the shock absorber handles separate vibration damping functions, achieving both drum stability and tub vibration separation.
4Loss of time
If the drum rotates through the transient region quickly to maintain high speed, then the spinning cycle time is reduced, but excessive vibration occurs
Solution Approach 1:
The control method employs periodic action by implementing a multi-phase rotation speed control strategy. The drum undergoes periodic acceleration and deceleration phases: first rotating at a controlled speed through the transient region to minimize vibration, then accelerating to a second rotation speed for efficient spinning, and potentially adjusting speed based on vibration feedback. This periodic speed adjustment minimizes time loss by quickly transitioning through vibration-prone regions while maintaining high speeds during stable spinning phases, optimizing the overall cycle time.
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 method effectively reduces drum vibration and noise by implementing balancing techniques, ensuring the drum and tub vibrations are separated, thereby enhancing the spinning cycle's efficiency and user experience.
Implementation Method 1
employing a rear gasket for sealing and a flexible supporting structure to reduce noise and vibration
Implementation Method 2
a suspension assembly connected to the driving unit
Data Source
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AI summary
The patent application discloses a control method of a laundry machine provided with a balancer. The method includes decreasing a speed of a drum (320) in case vibration of the drum (320) sensed in an accelerating step is a predetermined value or more and rotating the drum (320) at a constant speed for a predetermined time period to implement balancing.