Gas Turbine Fan Blade Tip Insert for Seal Durability

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing rotary fan blades for gas turbine engines face durability issues when engaging abradable seal materials, leading to potential damage and weight concerns due to the use of durable materials, and anodizing can cause cracking.

Innovation Solution

The design incorporates a slot in the blade tip between the pressure and suction side surfaces, with a tip insert extending chordwise along the slot, made from durable materials like titanium or anodized aluminum, to enhance mechanical strength and prevent damage during engagement with the abradable seal.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If durable materials are used for rotary blade tips to prevent damage during engagement with abradable seal, then blade tip durability is improved, but blade weight increases undesirably

Engineering Contradiction:
Improveblade tip durabilityVSAvoidblade weight
Core Design Contradiction:
ReliabilityVSWeight of moving object

Solution Approach 1:

The blade tip is segmented into a core structure and a separate tip insert. The insert is made of durable material (such as anodized aluminum or titanium) while the core remains lightweight. This segmentation allows the durable portion to be applied only where needed for engagement with the abradable seal, preventing full-blade material substitution and maintaining overall weight efficiency.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The tip insert provides localized durability enhancement at the blade tip region that engages with the abradable seal. By concentrating the durable material only at the tip rather than throughout the entire blade, the design achieves improved reliability at the critical engagement point while avoiding the weight penalty of making the entire blade more durable.

Inventive Principle:
Principle #3Local quality

2Strength

If anodizing is applied to rotary blade tips to strengthen them, then mechanical strength is improved, but cracking occurs in the fan blade

Engineering Contradiction:
Improveblade tip strengthVSAvoidblade integrity
Core Design Contradiction:
StrengthVSReliability

Solution Approach 1:

The blade is divided into the main airfoil structure and a separate tip insert. The anodizing process is applied only to the tip insert rather than the entire blade, isolating the thermal stress concentration to a small, replaceable component. This prevents cracking from propagating through the main blade structure while still providing the strength benefits of anodizing at the tip.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The tip insert is designed as a sacrificial or replaceable component that can withstand the harsh anodizing process and engage with the abradable seal. If damage or cracking occurs, only the insert needs replacement rather than the entire blade, making the system more economical and reliable despite the use of aggressive strengthening processes.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

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 design ensures the rotary fan blades are sufficiently durable to prevent tip damage and reduces weight, while minimizing galvanic corrosion, thereby improving mechanical durability and efficiency.

Implementation Method 1

made from durable materials like titanium or anodized aluminum, to enhance mechanical strength and prevent damage during engagement with the abradable seal

Methodology Applied
Scientific EffectMechanical strength:

Implementation Method 2

The design incorporates a slot in the blade tip between the pressure and suction side surfaces, with a tip insert extending chordwise along the slot

Methodology Applied
Scientific EffectMaterial removal:

Implementation Method 3

made from durable materials like titanium or anodized aluminum, to enhance mechanical strength and prevent damage during engagement with the abradable seal... minimizing galvanic corrosion

Methodology Applied
Scientific EffectGalvanic corrosion resistance:

Data Source

PatentEP2809885B1Rotary fan blade and corresponding assembly
Publication Date: 2019.12.25 UNITED TECH CORP
  • EP2809885B1 patent drawingFigure 1~2
  • EP2809885B1 patent drawingFigure 3~5
  • EP2809885B1 patent drawingFigure 6~11

AI summary

A rotary blade is provided that includes a root, an airfoil, and a tip insert. The airfoil is attached to the root, and has a suction side surface, a pressure side surface, a leading edge, a trailing edge, a tip, and a slot disposed within the tip. The slot extends in a chordwise direction between the leading edge and trailing edge. The tip insert has a base end and a rub end. The base end of the tip insert is disposed within the slot. The rub end of the tip insert extends radially outward from the airfoil tip.