Twisted Lead Wire RTD for Thermal Stress Resistance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing platinum temperature detectors are prone to disconnection due to thermal stress and mechanical vibrations, especially when used in high-temperature environments and under vibrational forces.
Innovation Solution
The design incorporates a metal conduit with a temperature detecting device and lead wires connected in a twisted state, along with a concentric pipe and ferrule for additional structural support, and epoxy is used to fill gaps and enhance robustness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If lead wires are connected to terminals using soldering, then electrical connection is established, but disconnection occurs due to thermal stress in high-temperature environments
Solution Approach 1:
The patent replaces the soldering connection (mechanical/chemical bond) with a twisted wire connection that relies on mechanical interlocking and friction. The lead wires are twisted around the terminal electrodes and secured with a protective tube, creating a mechanical connection that can withstand thermal stress without the limitations of soldering at high temperatures.
Solution Approach 2:
The patent applies preliminary action by pre-twisting the lead wires around the terminal electrodes before final assembly and securing them with protective tubes. This pre-established mechanical interlocking prepares the connection to withstand subsequent thermal stress and vibrations during operation.
2Reliability
If protective layers are formed at junctions, then stress relief is provided, but layers fall off due to vibrations and impact in high-temperature environments
Solution Approach 1:
The patent merges multiple protective functions into a single integrated structure. The protective tube serves both as a mechanical constraint to prevent wire loosening and as a stress-distributing element that reduces the impact of vibrations and impacts on the electrical connection, eliminating the need for separate protective layers.
Solution Approach 2:
The protective tube acts as a flexible shell that constrains the twisted wire connection. This flexible constraint allows the connection to accommodate thermal expansion and vibration while maintaining electrical contact, preventing the protective layer detachment problem seen in rigid layered structures.
3Reliability
If ferrule area is designed for wire connection, then electrical connection is achieved, but damage occurs from external forces when flow rate is high
Solution Approach 1:
The patent implements nesting by placing the twisted wire connection inside a protective tube, which is then inserted into the ferrule. This nested structure provides multiple levels of protection: the protective tube shields the wire connection from direct external forces, while the ferrule provides structural support, distributing the load and preventing damage to the electrical connection during high-flow operations.
Data Source
AI summary
Provided is a resistance temperature detector (RTD), and in particular, to an RTD that minimizes damage from thermal stress. The present disclosure is to solve the problem of electric wire disconnection caused by thermal stress and minimize damage due to a ferrule in a portion in which the ferrule is mounted.