Electrical Contact Cleaning via Mechanical Vibration
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Solution Overview
Problem
Electrical contacts in switching devices suffer from wear due to contamination and corrosion, leading to device failure, with existing cleaning methods either increasing service life but causing contamination buildup or shortening it through electric arcs.
Innovation Solution
A method involving mechanical vibration of electrical contact elements in a closed position using a waveform, which grinds the contacts to clean them efficiently and gently, avoiding sparks and high burn-off currents, and can be applied during operation to maintain contact closure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Duration of action of stationary object
If switching is performed in the currentless state to protect contacts, then service life is increased, but contamination and oxide films build up on contacts
Solution Approach 1:
The patent applies mechanical vibration to the contact elements during the currentless state to prevent contamination buildup. The vibration causes the contact surfaces to oscillate and grind against each other, maintaining cleanliness without requiring current flow or creating arcs. This resolves the contradiction by enabling contact protection without the harmful effect of contamination accumulation.
2Object-affected harmful factors
If switching is performed in the current applied state to clean contacts, then contaminations are removed, but service life is shortened due to electric arcs
Solution Approach 1:
The patent replaces the arc-based cleaning method with mechanical vibration during the currentless state. The vibration mechanically grinds away contaminants without creating electric arcs, thus removing contamination while preserving contact life. This eliminates the harmful arc discharge effect while maintaining the beneficial cleaning function.
3Productivity
If mechanical vibration is applied to clean contacts in closed position, then cleaning efficiency is improved and arcs are avoided, but additional control complexity is required
Solution Approach 1:
The patent utilizes the existing electromagnetic coil that actuates the contactor to generate mechanical vibration during the currentless state. By controlling the coil's energization pattern, the system self-generates the vibration needed for cleaning without requiring separate vibration generation components. This reduces control complexity while maintaining high cleaning efficiency.
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 method effectively self-cleans electrical contacts, reversing wear without adverse effects on service life, ensuring reliable operation of electrical switching devices, particularly in motor vehicle onboard electronics.
Implementation Method 1
applying a waveform on the electrical contact so that the first contact element and the second contact element are excited to undergo a mechanical vibration relative to each other
Implementation Method 2
the contact elements grind on or against each other in the closed position, resulting in a mechanical cleaning effect
Data Source
AI summary
A method for cleaning electrical contacts of an electrical switching device includes displacing a first electrical contact element and a second electrical contact element of an electrical contact relative to each other so that the first electrical contact element and the second electrical contact element are in a closed position; and when the first and second electrical contact elements are in the closed position applying a waveform on the electrical contact so that the first contact element and the second contact element are excited to undergo a mechanical vibration relative to each other.