Integrated Stretch Bolt for High Voltage Switchgear Connections
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Solution Overview
Problem
Existing electrical connection assemblies for circuit breakers and switchgears face issues with reliability due to exposed screw ends causing electrical problems, increased corrosion from multiple parts and transitions, and thermal losses, especially in outdoor applications.
Innovation Solution
Integrating the stretched bolt function into one of the current carrying parts, reducing the overall length and number of parts, and using materials like copper or aluminum, with potential embedding in insulation material to enhance mechanical strength and conductivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a stretched bolt with terminal and connector parts is used, then reliable electrical and mechanical contact is achieved, but the assembly length increases due to two threaded connections
Solution Approach 1:
The patent merges the bolt function directly into one of the current carrying parts by integrating the threaded connection features into the terminal or connector part itself. This eliminates the need for a separate stretched bolt component, thereby reducing the overall assembly length while maintaining the reliable electrical and mechanical contact through the integrated threaded connection.
2Reliability
If multiple parts with transitions and exposed edges are used, then electrical connection is achieved, but corrosion resistance deteriorates due to pollution and humidity accumulation
Solution Approach 1:
The patent reduces the number of separate parts by integrating the bolt function into one current carrying part. This merging eliminates multiple transitions and joints between separate components, thereby reducing the surfaces where pollution and humidity can accumulate, thus improving corrosion resistance while maintaining electrical connection reliability.
Solution Approach 2:
The patent extracts the exposed screw end from the assembly by integrating the threaded connection into the current carrying part itself. This eliminates the sharp edges and exposed surfaces that would otherwise accumulate pollution and moisture, thereby improving corrosion resistance without compromising the electrical connection.
3Reliability
If multiple separate parts are used for electrical connection, then connection functionality is achieved, but the number of parts and assembly complexity increases
Solution Approach 1:
The patent merges the bolt function into one of the current carrying parts by integrating the threaded connection features directly into the terminal or connector. This reduces the total number of separate parts in the assembly while maintaining all necessary connection functionalities, thereby simplifying the device complexity.
Data Source
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AI summary
The invention relates to a mechanical and electrical connection element for the use in medium and high voltage, for circuit breakers, reclosers and switchgears. In order to overcome the disadvantage, that the known design requires a certain length for two threaded connections, the invention is, that the connecting system comprises a stretch-bolt function, which is integrated in the first of the current carrying parts, and that the stretch bolt function is provided with a male screw thread at the extending end, which has to be screwed into a female threaded hole of the second current carrying part.