Washing Machine Dynamic Absorber for Transient and Continuous Oscillation

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Solution Overview

Problem

Existing dynamic absorbers in washing machines are limited in effectively absorbing transient oscillations due to viscoelastic member damage, low damping ratio, and increased risk of viscoelastic member deterioration, particularly when subjected to shear stress and horizontal oscillations.

Innovation Solution

A dynamic absorber design featuring a support plate with a moving mass that includes separate components for absorbing transient and continuous oscillations, utilizing elastic dampers and sliders to minimize friction and maximize absorption efficiency, with the moving mass slidably disposed on the support plate to counteract excitation forces effectively.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a viscoelastic member is disposed on the bottom surface of a moving mass to absorb oscillation, then the oscillation absorption function is provided, but the continuous load from the moving mass causes damage and performance deterioration of the viscoelastic member

Engineering Contradiction:
Improveoscillation absorption functionVSAvoidviscoelastic member durability
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The moving mass is divided into a first moving mass and a second moving mass, with the viscoelastic member positioned between them rather than supporting the entire load from one mass. This segmentation distributes the continuous load and prevents deterioration of the viscoelastic member while maintaining the oscillation absorption function.

Inventive Principle:
Principle #1Segmentation

2Reliability

If the moving mass oscillates horizontally using shear stress in the viscoelastic member, then the oscillation is absorbed, but the damping ratio is low and transient oscillation is not effectively absorbed

Engineering Contradiction:
Improveoscillation absorptionVSAvoiddamping ratio
Core Design Contradiction:
ReliabilityVSLoss of energy

Solution Approach 1:

The system transitions from static shear stress absorption to dynamic compression absorption. The second moving mass is configured to move vertically in response to horizontal oscillations, converting horizontal motion into vertical compression of the viscoelastic member. This dynamic response increases the damping ratio and effectively absorbs transient oscillations.

Inventive Principle:
Principle #15Dynamics

3Reliability

If the moving mass moves horizontally in opposition to oscillation, then horizontal oscillation is absorbed, but the moving mass tilts due to viscoelastic member bending and cannot maintain horizontal state

Engineering Contradiction:
Improvehorizontal oscillation absorptionVSAvoidmoving mass horizontal stability
Core Design Contradiction:
ReliabilityVSStability of the object's composition

Solution Approach 1:

The second moving mass acts as a counterweight that moves vertically in response to horizontal oscillations. This vertical movement counteracts the tilting effect caused by viscoelastic member bending, maintaining the horizontal stability of the moving mass system while continuing to absorb horizontal oscillations.

Inventive Principle:
Principle #8Anti-weight (Counterweight)

4Device complexity

If a single moving mass is used to absorb both transient and continuous oscillation, then the device structure is simple, but the absorption effectiveness across the entire drum speed range is reduced

Engineering Contradiction:
Improveabsorber structureVSAvoidoscillation absorption effectiveness
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The single moving mass is segmented into a first moving mass and a second moving mass with different functions. The first moving mass primarily absorbs continuous oscillation through horizontal movement, while the second moving mass absorbs transient oscillation through vertical movement. This segmentation enables effective oscillation absorption across the entire drum speed range.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system employs dynamic segmentation where the first and second moving masses move in different directions (horizontal and vertical respectively) in response to oscillations. This dynamic behavior allows each mass to specialize in absorbing specific types of oscillations, improving overall effectiveness without significantly increasing structural complexity.

Inventive Principle:
Principle #15Dynamics

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 design significantly reduces oscillation displacement and enhances the absorption of both transient and continuous oscillations, improving the stability and longevity of the washing machine by distributing loads and minimizing viscoelastic member stress.

Implementation Method 1

a viscoelastic member is disposed on a top surface of the frame, and a moving mass for absorbing oscillation is disposed on a top surface of the viscoelastic member

Methodology Applied
Scientific EffectViscoelasticity: Viscoelasticity

Implementation Method 2

utilizing elastic dampers and sliders to minimize friction and maximize absorption efficiency

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 3

the dynamic absorber harmonically oscillates at the resonant point in a phase difference of about 90 degrees with respect to the oscillation of the cabinet of the washing machine

Methodology Applied
Scientific EffectHarmonic oscillation: Harmonic Oscillator

Implementation Method 4

when the number of revolutions of the drum increases to reach the resonant frequency of the drum, the cabinet of the washing machine harmonically oscillates at a resonant point

Methodology Applied
Scientific EffectResonance: Resonance

Implementation Method 5

utilizing elastic dampers and sliders to minimize friction and maximize absorption efficiency

Methodology Applied
Scientific EffectLubrication: Lubrication

Data Source

PatentEP3266920B1Laundry treating apparatus
Publication Date: 2020.09.30 LG ELECTRONICS INC
  • EP3266920B1 patent drawingFigure 1
  • EP3266920B1 patent drawingFigure 2
  • EP3266920B1 patent drawingFigure 3

AI summary

A laundry treating apparatus is provided. The laundry treating apparatus includes a cabinet (11), a drum accommodated in the cabinet (11), and a dynamic absorber (20) provided to absorb oscillation of the cabinet (11). The dynamic absorber (20) includes a first moving mass (23) movably disposed on a support plate (21) to absorb oscillation transmitted to the cabinet (11) and a second moving mass (24) movably disposed on the support plate (21) to absorb oscillation transmitted to the cabinet (11). Each of the first and second moving masses (23, 24) includes a single mass made of a metal material or a mass in which a plurality of thin metal plates are coupled to overlap each other, and the first moving (23) mass has a mass greater than that of the second moving mass (23).