Injection Molded Composite Fan Platform for Gas Turbine Engines

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Solution Overview

Problem

Conventional discrete fan platforms in gas turbine engines tend to shift during operation due to pin attachment, are expensive to manufacture, and require complex assembly and disassembly processes, necessitating a lightweight, stable, and cost-effective solution.

Innovation Solution

The design incorporates a discrete fan platform with radially inwardly extending platform hooks retained to corresponding retention hooks on the rotor disk, featuring gussets for stiffness and injection-molded composite materials for reduced weight and manufacturing costs, along with contoured sides to match airfoil surfaces for aerodynamic flow.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If pin attachment is used for discrete fan platforms, then assembly is simplified, but the platforms tend to shift during engine operation

Engineering Contradiction:
Improveassembly simplicityVSAvoidplatform stability
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The attachment system is segmented into multiple independent hooks distributed around the platform perimeter, with each hook providing localized retention. This segmentation prevents shifting by distributing retention forces across multiple points rather than relying on a single pin attachment.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The retention mechanism transitions from a single-point pin attachment to multi-point hook engagement in different spatial dimensions. The hooks engage with corresponding features on the rotor disk from multiple angles, creating a three-dimensional retention system that prevents shifting while maintaining ease of assembly.

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

2Adaptability or versatility

If separate aluminum or composite components are used for fan platforms, then design flexibility is improved, but manufacturing cost increases

Engineering Contradiction:
Improvedesign flexibilityVSAvoidmanufacturing cost
Core Design Contradiction:
Adaptability or versatilityVSEase of manufacture

Solution Approach 1:

Multiple separate components (platform body, hooks, gussets) are merged into a single integrated injection-molded composite part. This consolidation eliminates the need for separate manufacturing processes for each component and eliminates assembly steps, significantly reducing manufacturing cost while maintaining design flexibility through the composite material's inherent properties.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The fan platform is manufactured as a single piece using injection-molded composite material, which combines the benefits of design flexibility with cost-effective manufacturing. The composite material allows for complex geometries to be formed in a single molding operation, eliminating the need for expensive multi-step assembly processes required for traditional aluminum or composite lay-up construction.

Inventive Principle:
Principle #40Composite materials

3Weight of moving object

If conventional discrete fan platforms are used, then weight reduction is achieved, but assembly and disassembly time increases

Engineering Contradiction:
Improveplatform weightVSAvoidassembly and disassembly time
Core Design Contradiction:
Weight of moving objectVSLoss of time

Solution Approach 1:

The platform body, hooks, and gussets are merged into a single pre-assembled injection-molded component. This eliminates the need for field assembly of multiple parts and reduces disassembly time when platforms need to be replaced, while maintaining the weight reduction benefits of using composite materials.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

All attachment features (hooks) and structural elements (gussets) are pre-integrated into the platform during manufacturing rather than being assembled in the field. This preliminary action of combining all components into a single unit during production eliminates time-consuming assembly operations during engine maintenance while preserving the lightweight characteristics.

Inventive Principle:
Principle #10Preliminary action

4Strength

If integral fan platforms are used with fan blades, then structural integrity is improved, but rotor disk size must be increased to accommodate centrifugal loads

Engineering Contradiction:
Improvestructural integrityVSAvoidrotor disk size
Core Design Contradiction:
StrengthVSArea of stationary object

Solution Approach 1:

The fan platform is segmented from the fan blade, creating a discrete platform that attaches to the rotor disk independently. This segmentation allows the platform to bear its own loads separately from the blade dovetail, enabling smaller dovetails and a smaller rotor disk while maintaining structural integrity through the platform's own attachment system.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The platform is extracted from the integral blade-platform structure and becomes a separate component with its own retention system. This extraction removes the requirement for the rotor disk to accommodate combined blade and platform centrifugal loads through larger dimensions, as the discrete platform's hooks provide independent load paths to the rotor disk.

Inventive Principle:
Principle #2Taking out (Extraction)

Data Source

PatentEP2971552B1Injection molded composite fan platform
Publication Date: 2020.09.23 RTX CORP
  • EP2971552B1 patent drawingFigure 1
  • EP2971552B1 patent drawingFigure 2~4

AI summary

A fan platform for a gas turbine engine may include an outer flow path surface extending between a first side and a second side. An inner surface extends between the first side and the second side, and faces radially oppositely the outer flow path surface. A plurality of platform hooks may extend radially inwardly from the inner surface.