Additively Manufactured Shaft Coupling for Torque and Flexibility

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Solution Overview

Problem

Drive shafts in aircraft require a balance between being stiff and strong under torque while also being flexible under axial and bending deformations, with current couplings being expensive due to high-precision fabrication and welding demands.

Innovation Solution

A metallic coupling design featuring spirally arranged layers of connectors with alternating spiral directions and angles relative to the center axis, manufactured using additive manufacturing to provide stiffness and flexibility, reducing costs through complex geometry fabrication.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If traditional diaphragm couplings with high-precision fabrication and welding are used, then torsional strength and stiffness are improved, but manufacturing cost and complexity increase

Engineering Contradiction:

Improvetorsional strengthVSAvoidmanufacturing cost

Core Design Contradiction:

StrengthVSEase of manufacture

Solution Approach 1:

The patent changes the manufacturing method from traditional high-precision machining and welding to additive manufacturing, fundamentally altering the production parameters. This enables complex geometries to be manufactured more economically while maintaining structural integrity and torsional strength through controlled material deposition and built-in flexibility features

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The coupling is segmented into multiple flexible diaphragms with specific geometric features that can be independently optimized. Each diaphragm contains flexibility features such as cutouts, holes, or varying thickness regions that provide controlled flexibility while maintaining overall structural strength, and these segmented features can be manufactured more efficiently using additive processes

Inventive Principle:

Principle #1Segmentation

2Strength

If traditional high-precision couplings are used, then structural rigidity under torque is improved, but flexibility under axial and bending deformations deteriorates

Engineering Contradiction:

Improvestiffness under torqueVSAvoidflexibility under deformation

Core Design Contradiction:

StrengthVSAdaptability or versatility

Solution Approach 1:

The coupling employs local quality by creating regions of different stiffness within the same structure. The diaphragms contain localized flexibility features such as cutouts, holes, or varying thickness distributions that concentrate flexibility in specific areas while maintaining rigidity in other regions. This allows the structure to be stiff under torque where needed while remaining flexible under axial and bending deformations

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent utilizes curved and spiral connector geometries instead of straight rigid connections. The spiral arrangement of connectors and the curved profiles of diaphragms provide inherent flexibility for axial and bending deformations while maintaining torsional stiffness through the geometric configuration. The curvature allows the structure to accommodate deformations more effectively

Inventive Principle:

Principle #14Spheroidality (Curvature)

3Ease of manufacture

If additive manufacturing with spiral connectors is used, then manufacturing cost and complexity are reduced, but achieving required torsional strength becomes more difficult

Engineering Contradiction:

Improvefabrication costVSAvoidtorsional strength

Core Design Contradiction:

Ease of manufactureVSStrength

Solution Approach 1:

The patent transitions from traditional planar or simple 3D connector designs to spiral connectors that utilize three-dimensional spatial arrangement. The spiral configuration adds a dimensional aspect that increases the effective length and structural efficiency of the connectors, providing enhanced torsional strength while maintaining the benefits of additive manufacturing for complex geometries

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

Data Source

PatentUS12607232B2Flexible metallic coupling for drive shafts made by additive manufacturing

Publication Date: 2026.04.21 GOODRICH CORP

AI summary

A metallic coupling for a drive shaft includes a first cylindrical flange extending axially along a center axis and a second cylindrical flange extending axially along the center axis and spaced axially from the first cylindrical flange. The metallic coupling also includes a first plurality and a second plurality of connectors. Each connector of the first plurality of connectors extends from the first cylindrical flange to the second cylindrical flange and are spaced circumferentially apart from each other about the center axis. Each connector of the second plurality of connectors also extends from the first cylindrical flange to the second cylindrical flange and are spaced circumferentially apart from each other about the center axis. The second plurality of connectors are radially inward from the first plurality of connectors relative to the center axis. An annular gap is radially between the first plurality of connectors and the second plurality of connectors.