Sheet Metal Blade Lock Retainer for Aircraft Engine Fan Assembly

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Solution Overview

Problem

Conventional blade lock retainers in aircraft engine fan assemblies are inefficient due to metal waste and require ultrasound inspection for cracks or voids created during forging, which increases production costs and complexity.

Innovation Solution

A blade lock retainer made from formed sheet metal, such as stainless steel, aluminum, or titanium alloys, manufactured through cutting, stamping, rolling, forming, punching, and bending, with integral annular ring portions and tab structures to securely couple with the blade lock and hub, reducing material waste and inspection needs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional metal forging and machining techniques are used to manufacture blade lock retainers, then the structural strength and reliability are improved, but metal waste is generated and ultrasound inspection is required to detect cracks or voids

Engineering Contradiction:

Improvestructural reliabilityVSAvoidmetal waste

Core Design Contradiction:

ReliabilityVSLoss of substance

Solution Approach 1:

The patent changes the manufacturing parameters from conventional forging and machining to sheet metal forming processes (cutting, stamping, rolling, forming, punching, and bending). This parameter change eliminates metal waste associated with subtractive machining while maintaining structural integrity through controlled forming operations that shape the sheet metal into the retainer configuration without creating voids or cracks

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent adopts a sheet metal construction approach that uses thin-gauge metal sheets (such as aluminum, stainless steel, or titanium alloys) instead of heavily forged metal components. This allows the retainer to be manufactured with minimal material waste while achieving the necessary structural performance through optimized forming and assembly design

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

2Reliability

If conventional metal forging and machining techniques are used to manufacture blade lock retainers, then the structural strength and reliability are improved, but subsequent ultrasound inspection is required to detect cracks or voids

Engineering Contradiction:

Improvestructural reliabilityVSAvoidinspection complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The sheet metal forming process produces retainers without the internal defects (cracks, voids, inclusions) that characterize forged components. The forming process creates a homogeneous structure that eliminates the need for costly ultrasound inspection, reducing device complexity in the manufacturing quality control system while maintaining reliability

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

Solution Approach 2:

The patent replaces the mechanical forging process with a sheet metal forming process. This substitution eliminates the harmful effects of forging (cracks, voids) that necessitate ultrasound inspection, thereby simplifying the overall manufacturing system by removing or reducing the inspection step

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Loss of substance

If sheet metal forming techniques are used to manufacture blade lock retainers, then material waste is reduced and inspection needs are eliminated, but the manufacturing process complexity increases with multiple steps including cutting, stamping, rolling, forming, punching, and bending

Engineering Contradiction:

Improvematerial wasteVSAvoidmanufacturing process simplicity

Core Design Contradiction:

Loss of substanceVSEase of manufacture

Solution Approach 1:

The sheet metal retainer is designed with segmented or modular features (such as the annular ring portion, tab portions, and finger structures) that can be formed through sequential stamping and forming operations. This segmentation allows each feature to be created in a dedicated process step, making the complex geometry manageable through standardized forming operations rather than requiring complex single-step manufacturing

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The sheet metal forming process serves multiple functions in sequence (cutting, stamping, rolling, forming, punching, bending) to create the complete retainer component. This multi-functionality consolidates what would otherwise require multiple separate manufacturing operations into a single integrated forming process, reducing overall manufacturing complexity despite the multiple steps involved

Inventive Principle:

Principle #6Universality (Multi-functionality)

Data Source

PatentEP3081758B1Aircraft engine fan assembly with a blade lock retainer

Publication Date: 2020.12.23 RTX CORP

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AI summary

The present disclosure provides devices related to aircraft engine fan assemblies (300) and blade lock retainers (210). In various embodiments, a blade lock retainer (210) is formed from sheet metal and comprises an annular ring portion (211), an outer retainer tab portion (212), and an inner tab portion (213). In various embodiments, the outer retainer tab portion (212) is disposed on an outer circumference of the annular ring portion (211), oriented substantially perpendicular to the annular ring portion (211), and extends in an aft direction from the annular ring portion (211). In various embodiments, the inner retainer tab portion (213) is disposed on an inner circumference of the annular ring portion (211) and radially aligned with the outer retainer tab portion (212), oriented substantially perpendicular to the annular ring portion (211), and extends in a forward direction from the annular ring portion (211).