Integrally Bladed Rotor Blade Repair Using Support Collar

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Repairing damaged rotor blades on integrally bladed rotors is challenging due to the lack of structural support during linear friction welding, particularly at the leading and trailing edges, which affects the formation of a robust and reliable bond, especially for small and thin blades in gas turbine engines.

Innovation Solution

A support collar with a contoured lower surface is used to provide additional structural support during linear friction welding, securing the blade stub within its internal cavity and connecting to the linear friction welding apparatus to ensure proper alignment and stability, allowing for a robust bond between the replacement blade segment and the blade stub.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If linear friction welding is used to bond replacement blade segments to blade stubs, then the repair can restore structural integrity, but insufficient structural support during welding leads to unreliable bonds

Engineering Contradiction:
Improvebond strengthVSAvoidrepair reliability
Core Design Contradiction:
StrengthVSReliability

Solution Approach 1:

A support collar is introduced as an intermediary component between the blade stub and the welding apparatus. The collar provides mechanical support and stabilization during the linear friction welding process, ensuring consistent bonding quality. The collar is removed after welding, having served its mediating function during the critical welding phase.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The support collar is installed on the blade stub before the welding operation begins. This preliminary action establishes the necessary structural support and alignment conditions prior to applying the welding process, preventing instability during the critical bonding phase.

Inventive Principle:
Principle #10Preliminary action

2Ease of repair

If small and thin blades are repaired using conventional methods, then blade replacement is possible, but lack of support during welding prevents robust bonding

Engineering Contradiction:
Improveblade repairabilityVSAvoidbond robustness
Core Design Contradiction:
Ease of repairVSStrength

Solution Approach 1:

The support collar serves as a specialized intermediary device designed to accommodate small and thin blade geometries. It provides the necessary support surface area and structural stability that these delicate blade components lack inherently, enabling successful welding where conventional direct bonding would fail.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Ease of manufacture

If replacement blade segments are bonded to blade stubs, then damaged blades can be restored, but alignment and stability during welding are insufficient

Engineering Contradiction:
Improverepair process feasibilityVSAvoidwelding alignment precision
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

The support collar is installed and positioned on the blade stub before the replacement blade segment is brought into place. This preliminary positioning establishes precise alignment references and stabilizes the blade stub, ensuring that subsequent bonding operations occur with the required precision and accuracy.

Inventive Principle:
Principle #10Preliminary action

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

The use of a support collar enhances the structural support during the welding process, resulting in a reliable and robust bond that maintains the original equipment manufacture properties, effectively addressing the challenges of repairing damaged rotor blades on integrally bladed rotors.

Implementation Method 1

linear friction welding apparatus

Methodology Applied
Scientific EffectFriction: Friction

Implementation Method 2

bonding a replacement blade segment to the blade stub by a linear friction welding operation

Methodology Applied
Scientific EffectFriction welding: Friction Welding

Data Source

PatentEP2339116B1Repair of integrally bladed rotors
Publication Date: 2014.03.12 UNITED TECH CORP
  • EP2339116B1 patent drawingFigure 1
  • EP2339116B1 patent drawingFigure 2~3
  • EP2339116B1 patent drawingFigure 4~8

AI summary

A method is provided for repairing a damaged rotor blade (22) on an integrally bladed rotor (20) by removing a damaged portion of a damaged blade leaving a blade stub (24) extending outwardly from the disk and performing a linear friction welding operation to attach a replacement blade segment to the blade stub (24). The rotor may be disposed operation using a linear friction welding apparatus (10). The method includes disposing a support collar (29) about the blade stub (24) -and securing the support collar (29) to the linear friction welding apparatus (10) prior to a commencement of the bonding operation. A lower surface of the support collar (29) is contoured to mate with a portion of an outer circumference surface of the rotor disk.