Composite Drive Shaft Grooves for Misalignment Flexibility

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Solution Overview

Problem

Drive shafts often face misalignment issues between input and output during operation, requiring enhanced flexibility, which existing designs with single tubular members and flexible diaphragms or grooves fail to adequately address.

Innovation Solution

A drive shaft with a tubular portion featuring deformations such as grooves or detents extending less than 180° around the central axis, formed from a fiber-reinforced polymer matrix material, providing axial spacing and varying groove densities to enhance flexibility and mitigate stress concentrations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a single tubular member with flexible diaphragms or grooves is used, then some flexibility is provided, but the flexibility is insufficient to adequately address misalignment issues

Engineering Contradiction:
ImproveflexibilityVSAvoidmisalignment accommodation
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The drive shaft is segmented into multiple modular sections that can independently deflect and rotate relative to each other. This segmentation allows the drive shaft to accommodate complex misalignments through cumulative angular deflections across multiple segments, providing superior flexibility compared to a single tubular member with limited diaphragms or grooves.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention introduces multi-directional flexibility by enabling deflection in multiple dimensions. Each modular section can deflect angularly in various directions and rotate about the longitudinal axis, transforming the single-dimensional flexibility of traditional grooves into multi-dimensional adaptability that effectively addresses complex misalignment issues.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Adaptability or versatility

If grooves extend across 360° on the shaft to provide flexibility, then flexibility is enhanced, but stress concentrations increase

Engineering Contradiction:
ImproveflexibilityVSAvoidstress concentration
Core Design Contradiction:
Adaptability or versatilityVSStress or pressure

Solution Approach 1:

Each modular section incorporates localized flexibility features such as grooves or bumps only in specific circumferential regions rather than extending 360° around the shaft. This local quality approach provides necessary flexibility at critical locations while maintaining structural integrity and reducing stress concentrations in other areas, optimizing the balance between flexibility and stress distribution.

Inventive Principle:
Principle #3Local quality

3Adaptability or versatility

If a fiber-reinforced polymer matrix material is used, then flexibility and stress distribution are improved, but manufacturing complexity increases

Engineering Contradiction:
ImproveflexibilityVSAvoidmanufacturing complexity
Core Design Contradiction:
Adaptability or versatilityVSEase of manufacture

Solution Approach 1:

The drive shaft utilizes fiber-reinforced polymer matrix composite materials that combine the flexibility and stress distribution benefits of composite structures with the modular segmented design. These composite materials provide enhanced toughness, fatigue resistance, and adaptability while the modular architecture simplifies manufacturing by allowing pre-fabrication of individual sections followed by assembly, reducing overall manufacturing complexity.

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 design achieves improved flexibility and reduced stress concentrations, effectively addressing misalignment issues and enhancing the operational performance of drive shafts in applications like aerospace.

Implementation Method 1

wherein the drive shaft is formed of a fiber-reinforced polymer matrix material

Methodology Applied
Scientific EffectComposite materials: Composite Materials

Implementation Method 2

Deformations are formed from an outer peripheral surface of the cylindrical shaft portion. The deformations extend for a circumferential extent that is less than 180° about a central axis of the tubular portion

Methodology Applied
Scientific EffectDeformation: Deformation

Implementation Method 3

providing axial spacing and varying groove densities to enhance flexibility and mitigate stress concentrations

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP3683461B1Drive shafts with enhanced bending flexibility
Publication Date: 2022.04.06 HAMILTON SUNDSTRAND CORP
  • EP3683461B1 patent drawingFigure 1~2C
  • EP3683461B1 patent drawingFigure 3A~3D
  • EP3683461B1 patent drawingFigure 4A~4D

AI summary

A drive shaft (26) has a tubular portion (31) extending between axial ends and is hollow. There are deformations on the tubular portions (31). The deformations extend for a circumferential extent that is less than 180° about a central axis of the tubular portion (31).