Laundry Machine Drum Balancer Control to Reduce Transient Vibration
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Solution Overview
Problem
Laundry machines face challenges in reducing drum vibration during high-speed rotation, particularly in the transient region where natural vibration modes occur, leading to unbalanced loads and increased vibration.
Innovation Solution
A control method that adjusts the positions of balancer balls to compensate for vibration modes, using a suspension assembly and rear gasket to isolate tub vibrations, and maintaining specific rotation speeds and ball configurations to minimize unbalance and vibration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the drum is rotated at high speed, then productivity is improved, but drum vibration increases due to transient region resonance
Solution Approach 1:
The control method performs preliminary actions by detecting unbalance before the drum enters the transient region and adjusting balancer ball positions in advance. The controller detects unbalance at a first rotation speed below the transient region, then adjusts the balancer balls to a predetermined position before accelerating through the transient region, thereby preventing vibration rather than reacting to it.
Solution Approach 2:
The invention changes operational parameters by using multiple rotation speeds: a first rotation speed for unbalance detection below the transient region, a second rotation speed for balancer adjustment, and a third rotation speed for passing through the transient region. By varying these parameters systematically, the system optimizes balancing effectiveness at different operational phases.
2Object-affected harmful factors
If balancer balls are positioned to compensate unbalance, then drum vibration is reduced, but the system becomes more complex
Solution Approach 1:
The balancer system operates autonomously through self-service mechanisms. The control method detects unbalance conditions and automatically adjusts balancer ball positions without requiring external intervention or complex control algorithms. The system uses simple detection and adjustment operations that leverage the natural behavior of the balancer balls under centrifugal force.
Solution Approach 2:
The balancer balls serve as intermediaries between the drum structure and the unbalance forces. Rather than directly counteracting vibrations through complex active control systems, the invention uses passive balancer balls that automatically migrate to positions that compensate for unbalance, simplifying the control architecture while maintaining effectiveness.
3Productivity
If the drum passes through the transient region quickly, then productivity is improved, but vibration and noise increase
Solution Approach 1:
The system performs preliminary balancing detection and adjustment before the drum enters the transient region. By detecting unbalance at lower speeds and pre-positioning the balancer balls, the system prepares the drum for smooth passage through the transient region, avoiding the need for slow passage that would reduce productivity while still minimizing vibration and noise.
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
Effectively reduces drum vibration by aligning balancer positions with vibration characteristics, allowing the drum to pass through transient regions with reduced unbalance and vibration, even in diagonal vibration modes.
Implementation Method 1
a balancer including a plurality of balls arranged in a radial direction of the drum and rotatable about a rotation axis of the drum
Implementation Method 2
positions of balls of a balancer by considering characteristics of a vibration mode at a transient region
Implementation Method 3
using a suspension assembly and rear gasket to isolate tub vibrations
Data Source
Figure 1
Figure 2
Figure 3~4
AI summary
A control method of a laundry machine is disclosed. The control method of laundry machine having a drum, a front balancer provided with a front portion of the drum and a rear balancer provided with a rear portion of the drum includes accelerating the drum and rotating the drum at a constant speed of a predetermined rotation speed for a predetermined time period, the predetermined rotation speed allowing that perpendicular displacement at the front portion of the drum is different from that at the rear portion of the drum.