Capacitor Housing with Overpressure Bead for Safety
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Solution Overview
Problem
Existing capacitors without overpressure cut-off mechanisms pose safety risks during overloads or breakdowns, particularly in sensitive environments, and the requirement for grounding increases installation complexity and cost, especially in space-constrained applications like refrigerant compressors.
Innovation Solution
A capacitor design with a cylindrical metal housing featuring a circumferential bead that unfolds upon overpressure, where the first section is surrounded by electrical insulation extending only up to the bead, eliminating the need for grounding connections and ensuring safety without compromising the overpressure mechanism's functionality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If P2 capacitors with grounding are used to meet safety standards, then safety is improved, but installation complexity and cost increase due to grounding requirements
Solution Approach 1:
The patent extracts the grounding requirement from the safety mechanism by using plastic insulation to provide electrical isolation instead. The metal housing is no longer required to be grounded because the plastic insulation around the first section provides the necessary electrical safety, eliminating the need for grounding connections while maintaining safety standards.
Solution Approach 2:
The patent changes the material parameter of the housing from conductive metal to electrically insulating plastic for the first section. This material parameter change fundamentally alters the electrical properties, allowing the housing to provide both mechanical protection and electrical insulation, thereby eliminating the need for separate grounding measures.
2Device complexity
If P0 capacitors without overpressure cut-off are used, then device complexity is reduced, but safety deteriorates as the capacitor can overheat, melt, and ignite flammable materials
Solution Approach 1:
The patent implements beforehand cushioning by providing a plastic housing that surrounds the capacitor winding and insulation. This plastic housing acts as a fire barrier that prevents ignition of flammable materials in the event of capacitor failure, thereby cushioning against the harmful effects before they can propagate. The housing is designed to contain potential failures and prevent them from causing external damage.
Solution Approach 2:
The patent uses composite construction combining metal housing for the first section with plastic insulation and plastic housing for the second section. This composite material approach provides both the mechanical strength of metal and the fire-resistant properties of plastic, creating a multi-functional housing that addresses both structural and safety requirements.
3Reliability
If additional protective housing is added to P0 capacitors to ensure safety, then safety is improved, but device complexity and space requirements increase
Solution Approach 1:
The patent merges the protective housing function with the capacitor structure itself. The plastic housing that surrounds the capacitor winding and insulation serves dual purposes: it provides mechanical protection and electrical insulation while also acting as the fire barrier. This integration eliminates the need for separate protective housings, reducing overall space requirements while maintaining safety.
Solution Approach 2:
The plastic housing performs multiple functions simultaneously: it provides electrical insulation, mechanical protection, and fire resistance. This multi-functionality eliminates the need for separate protective components, thereby reducing the overall volume and complexity of the capacitor assembly while maintaining comprehensive safety.
4Reliability
If grounding connections are provided for metal housing, then safety is improved, but manufacturing cost and installation complexity increase
Solution Approach 1:
The patent extracts the grounding requirement from the system by using plastic insulation to provide electrical isolation. The plastic material inherently provides electrical non-conductivity, eliminating the need for grounding connections and associated manufacturing steps, thereby reducing manufacturing cost and complexity.
Solution Approach 2:
The patent changes the electrical parameter of the housing material from conductive to insulating. This material parameter change eliminates the need for grounding connections, simplifying both manufacturing and installation processes while maintaining electrical safety through the insulating properties of the plastic material.
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 allows for safe operation of capacitors without grounding, simplifying production and installation while maintaining safety standards, even in critical environments, and is applicable for retrofitting existing capacitors.
Implementation Method 1
at least one circumferential bead (7) is formed in the jacket of the housing (6), which divides the housing (6) into a first section (8) and a second section (9) and can be unfolded by overpressure inside the housing
Implementation Method 2
the first section (8) of the housing (6) carries and is surrounded by electrical insulation (12), in particular made of plastic
Implementation Method 3
At least one of the connection lines (3) running inside the capacitor is stretched by the extension of the housing and tears at a predetermined breaking point (4)
Data Source
Figure 1~3
AI summary
The invention relates to an electric capacitor having at least one capacitor coil, a cylindrical housing that surrounds the capacitor coil, composed of metal, electric connectors, and connection lines that run in the housing interior and electrically connect the capacitor coil with the connectors, wherein at least one connection line has a planned breaking point, and wherein at least one circumferential depression is formed in the mantle of the housing, which depression divides the housing into a first segment and a second segment and can be unfolded by means of excess pressure in the housing interior, wherein the first segment surrounds the capacitor coil and the second segment carries the connectors.