Turbine Engine Pinion Web Lattice for Low-Mass Rim Stiffness

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Solution Overview

Problem

Existing aircraft turbomachine gear trains face challenges in reducing mass while maintaining mechanical performance, particularly in limiting deformation and vibrations of gable rims during operation.

Innovation Solution

The introduction of a reticulated structure within the gable's veil, which has a lower density than the front and rear walls, allows for mass reduction without compromising mechanical properties. This structure is manufactured using additive manufacturing techniques, enabling precise control over mechanical properties and distribution of efforts.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Weight of moving object

If the web is perforated to reduce mass, then mass is reduced, but mechanical performance deteriorates due to increased mixing losses and reduced structural integrity

Engineering Contradiction:
Improvemass of pinionVSAvoidmechanical performance of pinion
Core Design Contradiction:
Weight of moving objectVSStrength

Solution Approach 1:

The web incorporates a reticulated structure with controlled porosity, where the density of the reticulated structure is lower than the front and rear walls. This porous configuration reduces mass while maintaining structural integrity through the distributed lattice architecture, avoiding the harmful effects of through-perforations.

Inventive Principle:
Principle #31Porous materials

Solution Approach 2:

The pinion web combines solid wall regions with reticulated lattice regions to create a composite structure. This allows different areas to have optimized properties: solid walls provide strength at critical locations while the reticulated structure provides mass reduction in non-critical areas, resolving the contradiction between mass reduction and mechanical performance.

Inventive Principle:
Principle #40Composite materials

2Weight of moving object

If material is removed from the web to reduce mass, then mass is reduced, but deformation under load increases

Engineering Contradiction:
Improvemass of pinionVSAvoiddeformation of web and rim
Core Design Contradiction:
Weight of moving objectVSShape

Solution Approach 1:

The reticulated structure with controlled density provides a balance between mass reduction and structural stiffness. The lattice architecture distributes loads across multiple pathways, preventing excessive deformation while reducing mass compared to solid walls.

Inventive Principle:
Principle #31Porous materials

Solution Approach 2:

The web features non-uniform density distribution, with the reticulated structure having lower density than the front and rear walls. This local quality optimization places material strategically where needed for structural support while removing material from areas where it adds unnecessary mass.

Inventive Principle:
Principle #3Local quality

3Strength

If the web is solid to maintain mechanical performance, then mechanical performance is maintained, but mass is excessive

Engineering Contradiction:
Improvemechanical performance of pinionVSAvoidmass of pinion
Core Design Contradiction:
StrengthVSWeight of moving object

Solution Approach 1:

The reticulated structure provides a middle ground between solid and perforated configurations, offering mass reduction while maintaining adequate mechanical performance through the lattice architecture's load-distributing capabilities.

Inventive Principle:
Principle #31Porous materials

Solution Approach 2:

The combination of solid wall regions and reticulated structure creates a composite web that achieves mass reduction without sacrificing overall mechanical performance, as the solid walls provide critical strength while the reticulated structure provides structural continuity with reduced mass.

Inventive Principle:
Principle #40Composite materials

4Weight of moving object

If through-perforations are made in the web to reduce mass, then mass is reduced, but mixing losses increase

Engineering Contradiction:
Improvemass of pinionVSAvoidmixing losses
Core Design Contradiction:
Weight of moving objectVSLoss of energy

Solution Approach 1:

The reticulated structure uses a controlled porous lattice rather than through-perforations, reducing mass while minimizing disruptions to fluid flow paths and reducing mixing losses associated with abrupt openings.

Inventive Principle:
Principle #31Porous materials

Data Source

PatentEP3969786B1Pinion of a turbine engine shaft having a web comprising a cross-linked structure
Publication Date: 2025.04.09 SAFRAN HELICOPTER ENGINES
  • EP3969786B1 patent drawingFigure 1
  • EP3969786B1 patent drawingFigure 2a
  • EP3969786B1 patent drawingFigure 2b

AI summary

The present invention relates to a pinion for a gear train of an aircraft turbine engine, the pinion comprising: - a cylindrical body (2) extending along an axis and configured to engage with a shaft received in the cylindrical body, - a rim (4) concentric with the cylindrical body, - a web (3) defined axially by a front wall (32) and a rear wall (33) and extending radially from the cylindrical body to the rim, each of the front and rear walls having a density, the pinion comprising a cross-linked structure (5) around the cylindrical body between the front wall and the rear wall, the cross-linked structure comprising a unit cell repeated along three axes of a three-dimensional coordinate system, a density of the unit cell being strictly less than each of the densities of the front and rear walls.