Spiral Flexure Assembly for Thermal Expansion and Stiffness
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional flexure assemblies do not provide adequate torsional and radial stiffness for applications like gimbal assemblies, where materials with different thermal expansion coefficients can cause geometric distortions and material fatigue.
Innovation Solution
A flexure assembly comprising a first and second spiral flexure with nonlinear slots and counterposed orientation, along with spacing elements and fasteners, allows for thermal expansion while maintaining axial flexibility and minimizing radial and circumferential movement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If conventional flexure assemblies are used to accommodate thermal expansion, then thermal expansion is accommodated, but torsional and radial stiffness are insufficient
Solution Approach 1:
The patent employs spiral flexures with curved geometries instead of linear designs. The spiral configuration provides both thermal expansion accommodation and enhanced torsional/radial stiffness through its curved structure, resolving the contradiction between flexibility for thermal movement and structural rigidity.
Solution Approach 2:
The flexure assembly combines multiple materials with different thermal expansion coefficients in a composite structure. This allows the assembly to accommodate thermal expansion while maintaining structural integrity and stiffness through the synergistic properties of the composite materials.
2Strength
If rigid support is used for payload assembly, then torsional and radial stiffness are maximized, but thermal expansion causes geometric distortion
Solution Approach 1:
The support structure is segmented into multiple flexure elements rather than using a single rigid component. This segmentation allows different parts of the structure to move independently to accommodate thermal expansion while maintaining overall structural stiffness and geometric stability.
Solution Approach 2:
The patent changes the physical parameters of the flexure elements, including their geometry, material properties, and configuration, to create a structure that can dynamically adapt its stiffness characteristics in response to thermal conditions while maintaining geometric stability.
3Ease of manufacture
If linear slots are used in spiral flexures, then manufacturing is simplified, but torsional and radial stiffness are reduced
Solution Approach 1:
The patent replaces linear slots with curved or arc-shaped slots in the spiral flexures. This curvature increases the path length and structural complexity, thereby enhancing torsional and radial stiffness while still allowing for practical manufacturing through appropriate tooling and fabrication methods.
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 enhances torsional and radial stiffness, reducing material fatigue and distortion by allowing axial movement to accommodate thermal expansion, thereby improving positioning precision of coupled equipment.
Implementation Method 1
A flexure assembly of the present disclosure may be provided to accommodate the thermal expansion of materials of the rotatable component or assembly and/or the adjacent component or assembly
Implementation Method 2
Each of the plurality of slots of the first spiral flexure and the second spiral flexure can be nonlinear. For example, each of the plurality of slots of the first spiral flexure and the second spiral flexure can be arc shaped
Data Source
AI summary
A flexure assembly includes a first spiral flexure, a second spiral flexure, and a spacing element. The spacing element is positioned between the first spiral flexure and the second spiral flexure. The flexure assembly also includes a plurality of fasteners that collectively extend circumferentially around an axis defined by the flexure assembly. Each of the plurality of fasteners extends through the first spiral flexure and the second spiral flexure.