Circuit Breaker Insulating Cover Arc Protection
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Solution Overview
Problem
In existing circuit breakers, the separation of a mover and a stator generates high temperature high pressure arcs, which can melt metal components and weaken insulation by causing molten residue leakage, and using plastic shaft assemblies increases the device size.
Innovation Solution
A circuit breaker design incorporating an insulating cover that shields the metal components, preventing molten residue from leaking by accommodating the link and latch structures within recessed areas and using electrical insulators to fabricate the housing and cover, thereby maintaining insulation integrity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a metal shaft assembly is used in the circuit breaker, then the structural strength and durability are improved, but the metal component may be melted and leaked due to high temperature arc generated during mover-stator separation
Solution Approach 1:
An insulating cover made of heat-resistant insulating material is introduced as an intermediary protective layer between the metal shaft assembly and the arc. The cover includes a shaft assembly hole through which the metal shaft passes, but the material and structure of the cover prevent the arc from directly contacting and melting the metal components, thus resolving the contradiction between structural strength and arc resistance
Solution Approach 2:
The insulating cover creates a protected environment around the metal shaft assembly, effectively isolating it from the harmful arc environment. This is similar to creating an inert atmosphere that prevents direct interaction between the arc and metal components, allowing the metal shaft to maintain its structural strength without suffering arc-induced melting
2Object-affected harmful factors
If the shaft assembly is made of plastic to prevent melting, then the resistance to arc damage is improved, but the size of the circuit breaker increases
Solution Approach 1:
The protective function is segmented from the shaft assembly itself and placed in a separate insulating cover. This allows the shaft assembly to remain compact and functional while the cover provides the necessary arc protection. The segmentation enables the use of heat-resistant insulating material for protection without requiring the entire shaft assembly to be oversized
Solution Approach 2:
The insulating cover acts as a protective shell that encloses the metal shaft assembly. This thin-walled but heat-resistant cover provides arc protection while adding minimal volume to the overall circuit breaker design, thus preventing device size increase while maintaining arc resistance
3Ease of operation
If holes are provided in the housing for link structure operation, then the ease of operation is improved, but molten metal residue can leak through these holes and degrade insulation
Solution Approach 1:
The insulating cover serves as an intermediary barrier positioned between the internal components (shaft assembly and link structure) and the external environment. The cover includes appropriately sized holes that allow link operation but are surrounded by heat-resistant insulating material that prevents molten metal residue from escaping through these openings, thus maintaining insulation integrity while preserving operational accessibility
Solution Approach 2:
The insulating cover creates a protected internal environment that contains any molten metal residue generated during operation. The cover's material and structure prevent this residue from reaching the external environment through the holes, effectively maintaining an isolated zone that protects insulation integrity while allowing necessary operational movements
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
Prevents metal component melting and leakage, enhancing the insulating function and maintaining the circuit breaker's size without increasing it.
Implementation Method 1
When the mover is separated from the stator, a high temperature high pressure arc is generated from a contact between the mover and the stator
Implementation Method 2
an insulating cover (30) installed in the housing (10)... preventing molten residue from leaking
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A circuit breaker includes: a housing; a stator accommodated in the housing and connected to a terminal unit; a mover selectively brought into contact with the stator; an opening and closing unit manipulating the mover such that the mover is selectively brought into contact with the stator; and an insulating cover provided in the housing and shielding the mover and the stator from the exterior of the housing, wherein the housing or the insulating cover is made by molding an electrical insulating material.