Fan Blade Platform Assembly With Tab-Mounted Two-Part Platforms

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Solution Overview

Problem

Current gas turbine engine rotor systems face challenges in reducing size and cost, particularly in the design and attachment of fan blade platforms, which require complex manufacturing processes and unique platform designs for each rotor configuration, impacting weight, cost, and development time.

Innovation Solution

The solution involves a blade assembly where fan blades have tabs for attaching platform members directly, using fasteners, friction retention, or bonding with epoxy, allowing for a two-part platform construction that is mounted to the fan blade, eliminating the need for rotor-mounted platforms and simplifying assembly by attaching platforms to the fan blades before installation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If separate fan blade platforms are attached to the hub to reduce rotor blade size and cost, then manufacturing cost and blade size are reduced, but device complexity increases due to multiple attachment components (tabs, lugs, fasteners)

Engineering Contradiction:
Improvemanufacturing costVSAvoidattachment components
Core Design Contradiction:
Ease of manufactureVSDevice complexity

Solution Approach 1:

The patent combines the platform attachment function directly into the fan blade structure by integrating tabs into the blade root. This eliminates the need for separate hub-mounted lugs and complex multi-component attachment systems, thereby reducing device complexity while maintaining the cost benefits of separate platforms.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The fan blade tabs serve multiple functions: they provide structural support for the platform attachment, enable positioning of the platforms, and integrate with the blade root structure. This multi-functionality reduces the need for dedicated attachment components, simplifying the overall system.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Ease of manufacture

If outwardly extending tabs or lugs are forged onto the hub to accommodate separate fan blade platforms, then platform attachment is enabled, but weight increases due to additional hub material

Engineering Contradiction:
Improveplatform attachment capabilityVSAvoidhub weight
Core Design Contradiction:
Ease of manufactureVSWeight of stationary object

Solution Approach 1:

The patent extracts the attachment tab functionality from the hub structure and relocates it to the fan blade itself. This eliminates the need to forge additional material onto the hub, thereby preventing weight increase while maintaining platform attachment capability.

Inventive Principle:
Principle #2Taking out (Extraction)

3Reliability

If complex manufacturing processes are used for rotor-mounted platforms, then platform strength and reliability are improved, but manufacturing time and cost increase

Engineering Contradiction:
Improveplatform strengthVSAvoidmanufacturing efficiency
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent segments the platform into separate attachable components that can be manufactured independently using simpler processes, then assembled to the fan blade using the integrated tabs. This allows each component to be optimized for its specific function without requiring complex monolithic manufacturing processes.

Inventive Principle:
Principle #1Segmentation

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

This configuration reduces manufacturing complexity, weight, and cost by allowing for a standardized platform design that can be adapted to various fan blade configurations, enhancing reliability and simplifying assembly by eliminating separate hub-mounted platform installation.

Implementation Method 1

the bonding interface includes an epoxy to bond a material of the first platform member to the first side of the fan blade

Methodology Applied
Scientific EffectAdhesive bonding: Adhesive

Implementation Method 2

a friction retention interface is formed between the fan blade at the mounting region and a contact surface of the first platform on the first side

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP3819467B1Blade assembly for a gas turbine engine and gas turbine engine
Publication Date: 2022.07.27 RTX CORP
  • EP3819467B1 patent drawingFigure 1
  • EP3819467B1 patent drawingFigure 2
  • EP3819467B1 patent drawingFigure 3A~3B

AI summary

Blade assemblies (400; 700; 900a, 900b) for gas turbine engines are described. The blade assemblies include a fan blade (402; 502; 702; 902a, 902b) having a first tab (422; 524) extending from a leading edge (408; 508) and a second tab (422; 526) extending from a trailing edge (410; 510). A first platform (404; 604; 704; 904a, 904b) is affixed to a first side (412; 712) of the fan blade at the first and second tabs and a second platform (406; 606; 706; 906a, 906b) is affixed to a second side (414; 714) of the fan blade at the first and second tabs. At least one first fastener (420; 620; 920a, 920b) is arranged to connect the first platform, the first tab, and the second platform at a first end and at least one second fastener (420; 620; 920a, 920b) is arranged to connect the first platform, the second tab, and the second platform at a second end.