Cross-Blade Flexure Actuator for Precise Rotary-to-Linear Motion
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Solution Overview
Problem
Existing actuator systems for optical telescopes and similar applications are complex and heavy due to their numerous parts, which complicates precise positioning and control of optical elements over large distances with fine resolution.
Innovation Solution
An actuator system featuring a frame, a carriage, and a flexure assembly that constrains the carriage for linear motion, with cross-blade flexures and a rotary flexure converting rotary motion into linear motion while maintaining axial and lateral stiffness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional motor and screw designs (ball, roller, or lead screws) are used to achieve precise positioning, then positioning precision is improved, but device complexity and weight increase due to large number of parts
Solution Approach 1:
The patent combines multiple functions into a single integrated mechanism. The flexure assembly integrates the screw mechanism, bearing surfaces, and positioning elements into one monolithic structure, eliminating the need for separate motors, screws, and support components. This merging reduces part count while maintaining precision through the flexure's inherent elastic deformation characteristics.
Solution Approach 2:
The patent replaces traditional mechanical screw and bearing systems with a flexure-based mechanism. Instead of using friction-based screw threads and rolling elements, the invention uses elastic deformation of the flexure assembly to achieve precise linear motion from rotational input, eliminating complex mechanical assemblies.
2Measurement precision
If conventional motor and screw designs are used for precise positioning, then positioning precision is improved, but weight increases due to large number of parts
Solution Approach 1:
The patent combines multiple functions into a single integrated mechanism. The flexure assembly integrates the screw mechanism, bearing surfaces, and positioning elements into one monolithic structure, eliminating the need for separate motors, screws, and support components. This merging reduces part count while maintaining precision through the flexure's inherent elastic deformation characteristics.
Solution Approach 2:
The patent replaces traditional mechanical screw and bearing systems with a flexure-based mechanism. Instead of using friction-based screw threads and rolling elements, the invention uses elastic deformation of the flexure assembly to achieve precise linear motion from rotational input, eliminating complex mechanical assemblies.
3Device complexity
If flexure assembly with cross-blade flexures is used to reduce complexity, then device complexity is reduced, but maintaining axial and lateral stiffness becomes challenging
Solution Approach 1:
The patent employs composite structural design in the flexure assembly, combining multiple blade elements arranged in specific configurations. The cross-blade flexures and axial blades work together as a composite structure, where each blade contributes to overall stiffness in different directions, achieving both flexibility for motion and rigidity for stability.
Solution Approach 2:
The patent addresses stiffness requirements by transitioning from simple linear blades to three-dimensional cross-blade configurations. The blades are oriented at oblique angles and arranged in multiple dimensions, creating a spatial structure that provides stiffness in both axial and lateral directions while maintaining the ability to flex for motion.
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 system achieves precise and efficient conversion of rotary motion to linear motion with zero mechanical play, reducing complexity and weight, and enabling large distance actuation with fine distance resolution, such as on the order of microns or nanometers.
Implementation Method 1
cross-blade flexures operatively connect the carriage to the rotary base, the cross-blade flexures including a plurality of blade flexures and being oriented at an oblique angle to the rotary base and to the axis of the actuator system
Data Source
AI summary
An actuator system includes a frame configured to remain stationary relative to a carriage within the frame and connected to the frame by a flexure assembly configured to constrain the carriage for only linear motion along an axis of the actuator system. A rotary base is configured to receive rotational input. Cross-blade flexures operatively connect the carriage to the rotary base, the cross-blade flexures including a plurality of blade flexures and being oriented at an oblique angle to the rotary base and to the axis of the actuator system. A rotary flexure operatively connects the rotary base to the frame. The cross-blade flexures and the rotary flexure are configured to convert rotary motion of the rotary base into linear motion of the carriage and to maintain axial and lateral stiffness.