Out-of-Plane Inter-Stage Connections for Stiffer Flexure Mechanisms
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Flexure mechanisms in existing technologies face challenges in achieving ideal bearing behavior due to the trade-off between degrees of freedom (DoF) and degrees of constraint (DoC) stiffness, with parasitic compliance of rigid bodies leading to non-ideal stiffness properties.
Innovation Solution
The design incorporates inter-stage connections and reinforcement bodies to provide enhanced stiffness properties, utilizing parallelogram flexure modules and intermediate bodies to enhance constraint stiffness while maintaining desired degrees of freedom, leveraging elastic averaging and symmetry to improve load-bearing capabilities.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional flexure mechanisms are used to provide guided motion, then they are free of backlash, wear, and friction, but they exhibit parasitic compliance leading to non-ideal stiffness properties
Solution Approach 1:
The patent introduces inter-stage connections that extend in a third direction (out-of-plane) between reinforcement bodies of flexure blades. This spatial arrangement in multiple dimensions creates additional constraint paths that suppress parasitic compliance while preserving the frictionless motion characteristics of the flexure mechanism.
Solution Approach 2:
The patent employs a composite structural approach by combining multiple flexure blades with reinforcement bodies and inter-stage connections to form an integrated assembly. This composite structure achieves superior stiffness properties by distributing and combining the constraint functions across multiple components, while maintaining the elastic deformation-based motion capability.
2Strength
If inter-stage connections are added to enhance stiffness, then constraint stiffness is improved, but device complexity increases
Solution Approach 1:
The patent divides the flexure mechanism into modular components: flexure blades, reinforcement bodies, and inter-stage connections. Each component has a specific function, and they are assembled in a systematic manner. This segmentation allows for enhanced stiffness through additional components while maintaining manufacturability and assembly feasibility.
Solution Approach 2:
The inter-stage connections serve multiple functions simultaneously: they provide mechanical constraints in three or more degrees, connect reinforcement bodies across stages, and contribute to the overall structural rigidity. This multi-functionality reduces the need for separate components for each function, thereby limiting the increase in device complexity.
3Strength
If reinforcement bodies are incorporated into flexure blades, then out-of-plane stiffness is enhanced, but the trade-off between degrees of freedom and degrees of constraint becomes more challenging
Solution Approach 1:
The patent adds reinforcement bodies specifically at strategic locations on the flexure blades where out-of-plane stiffness is needed, rather than uniformly strengthening the entire structure. The inter-stage connections are positioned to provide constraints precisely where parasitic compliance occurs. This localized enhancement achieves the required stiffness while minimizing the impact on degrees of freedom and overall complexity.
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 enhanced flexure mechanism achieves improved stiffness in constraint directions while maintaining guided motion, reducing parasitic compliance and approaching ideal bearing behavior, suitable for precision engineering and micro- and nano-positioning applications.
Implementation Method 1
Flexure mechanisms can move by elastic deformation and, when they do, are largely free of backlash, wear, and friction
Data Source
AI summary
A multitude of flexure mechanism designs are set forth herein that furnish enhanced stiffness properties. The flexure mechanism designs can have various stages including ground stages, motion stages, flexure stages, and reinforcement stages, among other possible stages depending on the construction of the flexure mechanism designs. It has been determined that stages constituting twin stages can be connected via one or more inter-stage connections.