Temperature Probe Interference Fit for Fast Response
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing temperature probes with resistive elements mounted in protective housings suffer from slow response times due to air pockets and bonding agents, which hinder thermal conductivity and are inadequate for applications requiring rapid and accurate temperature measurements.
Innovation Solution
A temperature probe assembly featuring a thermally conductive housing and insert with a higher thermal coefficient of expansion, where the insert is tightly locked within the housing at elevated temperatures, eliminating the need for bonding agents and enhancing thermal contact for faster response times.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a resistive element is mounted within a protective housing using bonding agents, then the sensor is protected and structurally stable, but the response time increases to several seconds due to reduced thermal conductivity
Solution Approach 1:
The patent removes bonding agents and air pockets from the assembly by using a tapered insert that is interference-fit into the housing bore. This extraction eliminates the thermal barriers (bonding agents and air pockets) that caused slow response times, while the interference fit provides the necessary structural stability without requiring additional bonding materials.
Solution Approach 2:
The patent changes the thermal and dimensional parameters of the assembly by using a tapered insert with a higher coefficient of thermal expansion than the housing material. This parameter change allows the insert to expand more than the housing when heated, creating a tighter interference fit that maintains excellent thermal contact between the sensor, insert, and housing, thereby reducing response time while maintaining structural stability.
2Reliability
If bonding agents are used to secure the insert in the housing, then the assembly is structurally stable, but thermal conductivity is reduced and response time increases
Solution Approach 1:
The patent removes bonding agents from the assembly by using a tapered insert that is interference-fit into the housing bore. This extraction eliminates the thermal barriers (bonding agents and air pockets) that caused slow response times, while the interference fit provides the necessary structural stability without requiring additional bonding materials.
Solution Approach 2:
The patent uses a composite structure consisting of a tapered insert made from a material with a higher coefficient of thermal expansion than the housing material. This composite approach allows the insert to expand more than the housing when heated, creating a tighter interference fit that maintains excellent thermal contact between the sensor, insert, and housing, thereby reducing response time while maintaining assembly stability.
3Ease of manufacture
If air pockets are present between the element and housing, then manufacturing is easier, but thermal conductivity is considerably reduced resulting in slower response time
Solution Approach 1:
The patent changes the thermal and dimensional parameters of the assembly by using a tapered insert with a higher coefficient of thermal expansion than the housing material. This parameter change allows the insert to expand more than the housing when heated, creating a tighter interference fit that eliminates air pockets and maintains excellent thermal contact between the sensor, insert, and housing, thereby reducing response time while remaining manufacturable.
Solution Approach 2:
The patent utilizes thermal expansion by selecting a tapered insert material with a higher coefficient of thermal expansion than the housing material. When the assembly is heated during operation or assembly, the insert expands more than the housing, creating a tighter interference fit that eliminates air pockets and ensures excellent thermal contact, thereby reducing response time while maintaining ease of manufacture through the interference-fit design.
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
The solution achieves a significantly faster response time of at least 250 msec and higher accuracy in temperature measurements, with no need for bonding agents, while maintaining reliability and cost-effectiveness.
Implementation Method 1
The second thermally conductive material has a thermal coefficient of expansion that is greater than the first thermally conductive material, such that the insert is insertable into the inner bore at the first temperature and is tightly locked in the inner bore at a second temperature that is greater than the first temperature
Implementation Method 2
a housing formed of a first thermally conductive material and having an inner diameter defined by an inner bore, an insert formed of a second thermally conductive material disposed in the inner bore
Data Source
AI summary
A temperature probe assembly is provided. The temperature probe assembly may comprise a housing formed of a first thermally conductive material and having an inner diameter defined by an inner bore, an insert formed of a second thermally conductive material disposed in the inner bore and having an outer diameter that is substantially equal to the inner diameter of the housing at a first temperature and a temperature sensor mounted within the insert. The second thermally conductive material has a thermal coefficient of expansion that is greater than the first thermally conductive material, such that the insert is insertable into the inner bore at the first temperature and is tightly locked in the inner bore at a second temperature that is greater than the first temperature.