Multi-Axis Flexure Pivot for High-Load Angular Travel

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Solution Overview

Problem

Existing two-axis flexure devices have limited angular travel and are not capable of supporting large loads, making them unsuitable for applications requiring significant angular motion without compromising load capacity.

Innovation Solution

A multi-axis flexure device comprising a first and second support base, a central coupler, a first flexure device, and a second flexure device, each allowing rotation about a separate axis, with flexible members and couplers to facilitate relative rotation between support bases and the central coupler, increasing the range of angular motion to ±16 degrees while maintaining a load capacity of 1,000 Ibf.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If traditional bearings or bushings are used to allow pivot motion, then load transfer capability is improved, but wear, slop, and limited life occur

Engineering Contradiction:
Improveload transfer capabilityVSAvoidwear, slop, and limited life
Core Design Contradiction:
StrengthVSReliability

Solution Approach 1:

The patent replaces traditional mechanical bearings and bushings with a flexure-based mechanical system. The flexure pivot uses elastic deformation of flexural elements to enable pivot motion without contact surface displacement, eliminating friction, wear, and the need for lubrication while maintaining load transfer capability and providing unlimited life.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent changes the fundamental operating principle from contact-based rotation to elastic deformation-based rotation. By utilizing the elastic properties of flexural elements, the system achieves pivot motion through controlled bending and recovering, transforming the mechanical interaction from sliding/rolling contact to elastic strain, thereby eliminating wear and friction.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If flexural pivots are used to eliminate friction and wear, then reliability is improved, but angular travel range is limited

Engineering Contradiction:
Improvefrictionless operation and unlimited lifeVSAvoidangular travel range
Core Design Contradiction:
ReliabilityVSLength of moving object

Solution Approach 1:

The patent divides the flexure pivot into multiple independent flexural elements (first flexure and second flexure) that can each contribute to the overall angular travel. By segmenting the flexure structure, the system achieves increased total angular travel range while maintaining the reliability benefits of frictionless operation, as each flexural element operates within its elastic limits.

Inventive Principle:
Principle #1Segmentation

3Ease of manufacture

If flexural pivots are used to eliminate lubrication needs, then maintenance requirements are reduced, but load capacity is limited

Engineering Contradiction:
Improveno lubrication requiredVSAvoidload capacity
Core Design Contradiction:
Ease of manufactureVSStrength

Solution Approach 1:

The patent employs composite construction in the flexure pivot, combining multiple flexural elements and structural components to achieve high load capacity. The use of composite materials and multi-element construction allows the frictionless flexure mechanism to support substantial loads (e.g., 1,000 Ibf) while maintaining the advantage of requiring no lubrication or maintenance.

Inventive Principle:
Principle #40Composite materials

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 multi-axis flexure device provides increased angular travel and similar load capacity to traditional flexure devices, addressing the limitations of existing two-axis devices by enabling ±16 degrees of rotation in each axis while supporting substantial loads.

Implementation Method 1

angular motion is accomplished through flexing of elastic flexural elements

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP3870868B1Flexure device
Publication Date: 2023.03.22 RAYTHEON CO
  • EP3870868B1 patent drawingFigure 1
  • EP3870868B1 patent drawingFigure 2
  • EP3870868B1 patent drawingFigure 3~4

AI summary

A multi-axis flexure device comprising a first flexure of the first flexure device can be coupled to the first support base such that the first support base and the flexure coupler of the first flexure device relatively rotate about the first axis. A second flexure of the first flexure device can be coupled to the central coupler such that the central coupler and the flexure coupler of the first flexure device relatively rotate about the first axis. A first flexure of the second flexure device can be coupled to the second support base such that the second support base and the flexure coupler of the second flexure device relatively rotate about the second axis. A second flexure of the second flexure device can be coupled to the central coupler such that the central coupler and the flexure coupler of the second flexure device relatively rotate about the second axis.