Thermally Stabilized Fastener Assembly for Thermal Load Compensation

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Solution Overview

Problem

Existing fastener systems fail to maintain constant clamping forces across varying temperatures due to mismatched thermal expansion coefficients between materials, leading to loosening or over-tightening, which causes fatigue and equipment failure in industrial and aerospace applications.

Innovation Solution

The development of thermally stabilized fastener systems that incorporate tailored thermal expansion coefficient materials, which expand or contract opposite to other metals, maintaining constant mechanical load through the use of temperature compensating members that complement the thermal expansion characteristics of conventional fasteners and retention receivers.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional fasteners are used, then the fastening system is simple and easy to manufacture, but the clamping force varies with temperature causing loosening or over-tightening

Engineering Contradiction:

Improveclamping force stabilityVSAvoidfastener system structure

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent changes the thermal expansion parameter by introducing a temperature compensating member with a specific coefficient of thermal expansion that differs from conventional fasteners. This member is designed to expand or contract in opposition to the fastener's thermal expansion, thereby compensating for temperature-induced dimensional changes and maintaining stable clamping force across varying temperatures.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The fastening system employs composite material construction by combining the conventional fastener (typically metal) with a temperature compensating member made from materials exhibiting opposite thermal expansion characteristics. This composite approach allows the system to leverage the strength and fastening capability of metal fasteners while incorporating the thermal compensation properties of specially selected materials to counteract thermal effects.

Inventive Principle:

Principle #40Composite materials

2Reliability

If temperature compensating members are added, then clamping force stability is improved, but the fastener system becomes more complex

Engineering Contradiction:

Improveclamping force consistencyVSAvoidnumber of components

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The temperature compensating member serves as an intermediary element positioned within the fastening system between the fastener and the joined components. It mediates the thermal expansion effects by absorbing or counteracting dimensional changes, thereby protecting the fastening interface from temperature-induced stress variations and maintaining consistent clamping force without requiring fundamental redesign of the entire fastening system.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Reliability

If fasteners are subjected to temperature variations, then thermal expansion mismatch occurs, but adding compensation mechanisms increases manufacturing complexity

Engineering Contradiction:

Improveresistance to thermal looseningVSAvoidassembly process simplicity

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The invention modifies the thermal parameter of the fastening system by incorporating a member with a tailored coefficient of thermal expansion. This parameter change enables the system to automatically compensate for thermal effects through the physical property of the material itself, rather than requiring complex active control mechanisms or multiple adjustment steps during assembly and manufacturing.

Inventive Principle:

Principle #35Parameter changes

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 solution ensures that fasteners maintain constant clamping forces across a wide temperature range, reducing the risk of loosening or over-tightening, thereby enhancing the reliability and safety of industrial and aerospace equipment by compensating for the natural expansion and contraction of materials.

Implementation Method 1

tailored thermal expansion coefficient materials, which expand or contract opposite to other metals

Methodology Applied

Scientific EffectThermal expansion: Thermal Expansion

Implementation Method 2

tailored thermal expansion coefficient materials, which expand or contract opposite to other metals

Methodology Applied

Scientific EffectNegative thermal expansion: Negative Thermal Expansion

Data Source

PatentUS11846307B2Thermally stabilized fastener system and method

Publication Date: 2023.12.19 MONROE JAMES ALAN

AI summary

A thermally stabilized fastener system and method is disclosed. The disclosed system/method integrates a fastener (FAS) incorporating a faster retention head (FRH), fastener retention body (FRB), and fastener retention tip (FRT) to couple a mechanical member stack (MMS) in a thermally stabilized fashion using a fastener retention receiver (FRR). The MMS includes a temperature compensating member (TCM), a first retention member (FRM), and an optional second retention member (SRM). The TCM is constructed using a tailored thermal expansion coefficient (TTC) that permits the TCM to compensate for the thermal expansion characteristics of the FAS, FRM, and SRM such that the force applied by the FRH and FRR portions of the FAS to the MMS is tailored to a specific temperature force profile (TFP) over changes in MMS/FAS temperature. The TCM may be selected with a TTC to achieve a uniform TFP over changes in MMS/FAS temperature.