Monolithic Compound Flexure for High Off-Axis Stiffness

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Solution Overview

Problem

Conventional mechanisms for providing linear motion in devices, such as optical instruments, suffer from issues like optical alignment slippage, susceptibility to high loads, complex design, and challenging assembly processes, particularly in dynamic environments like satellite launches.

Innovation Solution

A compound flexure mechanism with a monolithic structure comprising a frame and a flexure, where the flexure is movable relative to the frame, and an actuator is used to adjust the position of the device, providing high off-axis stiffness and straight motion, while allowing for easy manufacturing and scalability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If conventional flexure bearings are used to provide linear motion, then linear movement is permitted, but rotational movement is reduced or prevented, however optical alignment slippage occurs and susceptibility to undesirable deviations from desired motion paths increases

Engineering Contradiction:

Improveoptical alignment stabilityVSAvoidmotion path accuracy

Core Design Contradiction:

Stability of the object's compositionVSReliability

Solution Approach 1:

The patent combines the frame and flexure into a monolithic structure formed from a single piece of material, eliminating the need for separate flexure bearings. This integration resolves the contradiction by providing both linear motion capability and rotational constraint within a unified structure, preventing optical alignment slippage while maintaining motion path accuracy through the inherent rigidity and precision of the monolithic design

Inventive Principle:

Principle #5Merging (Combining)

2Ease of operation

If conventional mechanisms are used for linear motion, then motion is provided, but design complexity increases and assembly processes become challenging

Engineering Contradiction:

Improveease of assemblyVSAvoidmechanism design complexity

Core Design Contradiction:

Ease of operationVSDevice complexity

Solution Approach 1:

By merging the frame and flexure into a single monolithic structure, the patent dramatically simplifies the design and assembly process. Instead of assembling multiple separate components with precise alignment requirements, the entire mechanism is formed from one piece of material, eliminating complex assembly procedures while reducing design complexity through the unified structural approach

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The monolithic structure is designed with integrated flexure elements that are segmented within the single piece, allowing independent movement of specific portions while maintaining overall structural integrity. This internal segmentation provides the necessary linear motion capability without requiring external assembled components

Inventive Principle:

Principle #1Segmentation

3Strength

If conventional flexure mechanisms are used, then linear motion is achieved, but vulnerability to high loads during launch increases

Engineering Contradiction:

Improveload resistanceVSAvoidlaunch phase reliability

Core Design Contradiction:

StrengthVSReliability

Solution Approach 1:

The monolithic structure combines the frame and flexure into a unified load-bearing system that can better distribute and withstand high launch loads. The integrated design eliminates weak interfaces between separate components, providing enhanced strength and reliability during the high-stress launch phase while maintaining linear motion capability

Inventive Principle:

Principle #5Merging (Combining)

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 significantly reduces off-axis movement, enhances assembly simplicity, and improves performance by providing high off-axis stiffness, minimizing the risk of performance degradation under dynamic loads and allowing for precise linear motion.

Implementation Method 1

a flexure (25) located within the frame (23). The flexure (25) is movable relative to the frame (23), and the frame (23) and the flexure (25) form at least part of a monolithic structure

Methodology Applied

Scientific EffectElasticity: Elasticity

Implementation Method 2

A post flexure (39) of the compound flexure (21) extends along the axis (35) and engages the flexure (25)

Methodology Applied

Scientific EffectMechanical constraint through flexural engagement:

Data Source

PatentUS11258158B2Apparatus and method for providing linear motion of a device

Publication Date: 2022.02.22 RAYTHEON CO

AI summary

A system includes a compound flexure having a frame, a flexure, and a post flexure. The frame has an axis, and the flexure is located within the frame. The flexure is movable relative to the frame, and the frame and the flexure form at least part of a monolithic structure. The post flexure extends along the axis and engages the flexure. The system also includes a device coupled to the flexure and configured to move with the flexure relative to the frame. The system further includes an actuator coupled to the flexure and configured to move the flexure and the device relative to the frame.