Washing Machine Leg Rubber Composition for Resonance Damping
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Solution Overview
Problem
Existing drum-type washing machines experience amplified vibration due to resonance between the outer cabinet and spin tub during the dry cycle, as the spin speed matches the natural frequency of the machine, leading to insufficient vibration reduction despite the use of elastic leg rubbers and anti-vibration dampers.
Innovation Solution
An anti-vibration rubber with a high loss factor, specifically designed for temperatures between 0°C to 40°C, is used for the washing machine's leg rubbers, composed mainly of halogenated butyl rubber with a metal oxide as a vulcanizing agent and a tackifying resin with a melting point of 120°C or higher, to maintain effective vibration reduction across the machine's operational temperature range.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional elastic leg rubbers are used, then the washing machine can operate normally, but vibration is amplified when spin speed matches the natural frequency of the body
Solution Approach 1:
The patent changes the material parameters of the leg rubber by specifying a loss factor of 0.2 or more at -10°C and 10 Hz, and 0.15 or more at 40°C and 10 Hz. This parameter optimization ensures the rubber maintains adequate damping properties across the operating temperature range, preventing resonance amplification while supporting the washing machine body.
Solution Approach 2:
The patent employs a composite rubber composition containing specific additives and fillers to achieve the desired loss factor characteristics. The composite material formulation includes rubber base, vulcanizing agent, and other components in specific proportions to create a material that maintains consistent damping performance across temperature variations.
2Productivity
If the spin speed is increased for the spin cycle, then centrifugal force increases to squeeze out water, but the body may resonate with the spin speed
Solution Approach 1:
The patent converts the harmful resonance effect into a beneficial damping effect by designing the leg rubber with specific loss factor characteristics. The rubber material absorbs and dissipates the vibrational energy generated during high-speed spinning, transforming the harmful resonance into heat energy through internal friction, thereby reducing vibration while maintaining high spin speed for water extraction.
3Ease of operation
If the washing machine is used in the intermediate spin speed region, then it passes through the natural frequency region, but vibration is amplified
Solution Approach 1:
The patent applies beforehand cushioning by pre-designing the leg rubber with optimized damping characteristics before the washing machine operates. The rubber composition and formulation are specifically tailored to provide maximum damping in the intermediate speed region where resonance occurs during cycle transitions, cushioning the harmful vibrations before they can amplify.
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 anti-vibration rubber significantly reduces vibration and noise by maintaining a high loss factor in the lower spin speed region, effectively mitigating resonance issues and improving the overall operational stability of the washing machine.
Implementation Method 1
an anti-vibration rubber having a high loss factor in this lower spin speed region
Implementation Method 2
a loss factor of 0.5 or more in an entire temperature range of 0°C to 40°C, both inclusive, at the frequency of 10 Hz
Data Source
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AI summary
An anti-vibration rubber of the present invention is an anti-vibration rubber for washing machines. In temperature variance measurement of dynamic viscoelasticity at a frequency of 10 Hz, the anti-vibration rubber has a maximum loss factor at a temperature of 0°C to 40°C, both inclusive, and has a loss factor of 0.5 or more in the entire temperature range of 0°C to 40°C, both inclusive, at the frequency of 10 Hz.