Modular Cardan Joint Spider Assembly for Lower Weight and Torsion Stiffness

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing cardan joint spiders in rocket engines are heavy, expensive, and prone to manufacturing defects due to complex production methods, which result in high mechanical stress and weight issues.

Innovation Solution

A cardan joint spider design featuring a cross-shaped body composed of four right-angled brackets with perpendicular arms, stiffeners, and a bolt-fastening system that simplifies assembly, reduces weight, and enhances stiffness, thereby minimizing deformation under torsion and bending stresses.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If cardan joint spiders are made from forged metal or single-piece castings to withstand high mechanical stress, then strength is improved, but weight increases and manufacturing complexity increases

Engineering Contradiction:

ImprovestrengthVSAvoidweight

Core Design Contradiction:

StrengthVSWeight of moving object

Solution Approach 1:

The spider is divided into four separate bracket components that are assembled together to form the complete cross-shaped structure. Each bracket can be manufactured independently using simpler processes, reducing overall manufacturing complexity and weight while maintaining structural integrity through the assembly of multiple parts

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The spider structure combines multiple bracket components into a composite assembly that achieves the required strength through the collective performance of its parts rather than requiring a single heavy forged or cast piece. This composite approach allows for optimized material usage and reduced weight

Inventive Principle:

Principle #40Composite materials

2Strength

If cardan joint spiders are made from forged metal or single-piece castings to withstand high mechanical stress, then strength is improved, but manufacturing complexity increases and defect risk increases

Engineering Contradiction:

ImprovestrengthVSAvoidmanufacturing complexity

Core Design Contradiction:

StrengthVSEase of manufacture

Solution Approach 1:

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The design changes the manufacturing approach from monolithic forging or casting to modular assembly of brackets with standardized fastening parameters. This allows for more controllable manufacturing processes with lower defect risks while achieving the required mechanical strength

Inventive Principle:

Principle #35Parameter changes

3Stability of the object's composition

If stiffeners are added to improve stiffness and reduce deformation under torsion stresses, then rigidity is improved, but device complexity increases

Engineering Contradiction:

ImprovestiffnessVSAvoiddevice complexity

Core Design Contradiction:

Stability of the object's compositionVSDevice complexity

Solution Approach 1:

Stiffeners are added specifically to the bracket components where they are most needed to resist torsion stresses and prevent deformation. This localized reinforcement approach improves overall rigidity without unnecessarily complicating the entire spider structure, as stiffeners are only placed in critical areas

Inventive Principle:

Principle #3Local quality

4Ease of manufacture

If a bolt-fastening system is used to assemble brackets and stiffeners, then ease of manufacture is improved and weight is reduced, but device complexity increases

Engineering Contradiction:

Improveease of manufactureVSAvoiddevice complexity

Core Design Contradiction:

Ease of manufactureVSDevice complexity

Solution Approach 1:

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The bolt-fastening system merges the assembly of multiple bracket components and stiffeners into a cohesive spider structure. This modular assembly approach simplifies manufacturing and inspection while the standardized fastening system actually reduces overall complexity compared to monolithic construction

Inventive Principle:

Principle #5Merging (Combining)

Data Source

PatentUS11739797B2Cardan joint spider

Publication Date: 2023.08.29 ARIANEGRP SAS

AI summary

A cardan joint spider comprising a body having four right-angled brackets, each bracket presenting two mutually perpendicular arms, the arm of one bracket being assembled to the arm of an adjacent bracket so as to form a cross-shaped spider having four branches.