Flexure Pivot Structure for Precise Rotation Without Translation

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Solution Overview

Problem

Commercial off-the-shelf flexural pivots face issues with repeatable performance and reliability, particularly in applications requiring high performance and durability, due to their complex designs and challenging manufacturing processes.

Innovation Solution

A novel flexural pivot design utilizing an outer member and inner member flexure system with co-located flexure endpoints, allowing for fine rotational adjustments through additive manufacturing, which includes a flexure system positioned within a spherical and platonic-shaped cavity, enabling rotational movements without translation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If commercial off-the-shelf flexural pivots are used, then ease of acquisition is improved, but reliability and repeatable performance deteriorate due to complex designs and manufacturing difficulties

Engineering Contradiction:

Improveease of acquisitionVSAvoidrepeatable performance

Core Design Contradiction:

Ease of manufactureVSReliability

Solution Approach 1:

The flexural pivot is divided into discrete components: an outer member with spherical cavity, an inner member with platonic shape, and multiple flexure elements. This segmentation allows each component to be manufactured separately using additive manufacturing, improving reliability through modular assembly while maintaining ease of acquisition.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent changes the geometric parameters of the flexure elements and the cavity shapes to optimize performance. The spherical outer cavity and platonic inner shape create specific geometric relationships that improve rotational precision and reliability while maintaining manufacturability through standardized additive manufacturing processes.

Inventive Principle:

Principle #35Parameter changes

2Reliability

If complex flexural pivot designs are used, then functional performance is improved, but device complexity and manufacturing difficulty increase

Engineering Contradiction:

Improvefunctional performanceVSAvoiddesign complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The flexure elements serve multiple functions simultaneously: they provide rotational compliance, constrain translational movement, and enable the spherical-to-platonic shape transformation. This multi-functionality reduces overall design complexity while maintaining high functional performance through integrated component design.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The inner member with platonic shape is positioned within the spherical cavity of the outer member, creating a nested configuration. This nesting arrangement simplifies the overall structure by combining multiple functional requirements into a compact, hierarchical design that is easier to manufacture while maintaining performance.

Inventive Principle:

Principle #7Nested doll (Nesting)

3Manufacturing precision

If traditional manufacturing methods are used, then manufacturing precision can be achieved, but productivity and cost-effectiveness deteriorate

Engineering Contradiction:

Improvemanufacturing precisionVSAvoidproduction efficiency

Core Design Contradiction:

Manufacturing precisionVSProductivity

Solution Approach 1:

The patent replaces traditional mechanical manufacturing processes with additive manufacturing technology. This substitution enables direct fabrication of the complex spherical and platonic geometries with high precision while significantly improving productivity through rapid prototyping and batch production capabilities, reducing both time and cost.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

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 design provides high performance and reliability with simplified production, achieving fine positional adjustments for stabilizing a line of sight between a sensor and a target, reducing friction and lubrication needs.

Implementation Method 1

Because angular motion is accomplished through flexing of elastic flexural elements, rather than contact surface displacement, flexural pivots operate without friction and thus without a need for lubrication.

Methodology Applied

Scientific EffectElasticity: Elasticity

Data Source

PatentUS20260029233A1Rotational flexure pivot

Publication Date: 2026.01.29 RAYTHEON CO

AI summary

Embodiments of the disclosure are directed to a structure operable to perform compensation movements. The structure includes a flexure system that includes an outer member (OM) flexure system associated with an outer member; and an inner member (IM) flexure system associated with an inner member. The OM flexure system includes OM flexures having first OM flexure endpoints, and the IM flexure system includes IM flexures having first IM flexure endpoints. The structure further includes a common flexure endpoint that includes the first IM flexure endpoints co-located with the first OM flexure endpoints. The IM flexures include a first IM flexure mechanically coupled to the inner member, and the OM flexures include a first OM flexure mechanically coupled to the outer member. The compensation movements include the inner member and the outer member moving with respect to one another.