Concentric Embossed Appliance Walls to Suppress Resonance Noise
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Solution Overview
Problem
Household appliances with cabinet-like housings experience unwanted noise and stress due to vibrations, particularly in washing machines, despite the use of stiffeners and embossings, as multiple surface sections with similar resonant frequencies amplify noise.
Innovation Solution
The arrangement of embossings on the side walls, featuring a centered ring-shaped first embossing, concentric ring-shaped second embossing, and strip-shaped third embossing, all curved inward with fibers at their edges, significantly reduces vibrations and noise by minimizing resonance amplification.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If multiple congruent embossings are arranged uniformly on the wall, then the structural stability is improved, but the vibrations are amplified due to resonant frequency matching
Solution Approach 1:
The patent applies asymmetry by using embossings with different geometries (ring-shaped, concentric ring-shaped, and strip-shaped) and different sizes. This asymmetric arrangement ensures that each embossed surface section has a different resonant frequency, preventing vibration amplification while maintaining structural stability through the distributed stiffening effect of multiple embossings.
2Ease of manufacture
If flat wall surfaces are used in the housing, then the manufacturing is simpler, but the vibrations lead to increased noise and stress on the housing
Solution Approach 1:
The patent applies curvature by forming embossings that bulge inward into the housing interior. These curved embossed surfaces increase the structural rigidity of the walls without requiring complex manufacturing processes, as the embossings can be formed using standard stamping or molding techniques. The curved geometry effectively reduces vibration and noise while maintaining ease of manufacture.
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 design enhances the stability and reduces noise in household appliances by minimizing vibration transmission, achieving a 100% increase in rigidity and shifting natural frequencies above the rotational frequency of laundry drums, resulting in smoother operation.
Implementation Method 1
it was not considered that when a plurality of congruent surface sections are formed, each individual surface section acts as an oscillatable membrane with its own resonant frequency. Several equal surface sections with the same resonant frequency lead to an amplification of the noise generated by the vibration exciter at this very frequency.
Data Source
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AI summary
The invention relates to a household appliance (1) that has a cabinet-shaped housing (2) comprising a plurality of walls (3, 4, 5, 6, 7, 8), at least one of which has an arrangement of embossings (9, 10, 11). The arrangement of embossings (9, 10, 11) includes a first embossing (9) that has the shape of a circle when viewed from above and is centrally located relative to a center of the wall (3, 4, 5, 6, 7, 8), a second embossing (10) that also has the shape of a circle when viewed from above and is arranged outside and substantially concentrically to the first embossing (9), and at least one strip-shaped third embossing (11) that is arranged outside the second embossing (10). Said type of embossings (9, 10, 11) in the wall (3, 4, 5, 6, 7, 8) has the advantage of drastically reducing vibrations, which in turn significantly reduces the amount of unwanted noise.