Gas Turbine Blade Tip Repair via Electrical Discharge Machining

Solution Overview

Problem

Conventional methods for repairing worn or damaged tip pockets and cooling holes in gas turbine engine blades are time-consuming and expensive, requiring welding and machining processes that are inefficient.

Innovation Solution

A repair tool with a conductive material body and pins complementary to the blade tip pocket geometry, used in conjunction with electrical discharge machining to restore the original shape and configuration of the tip pockets and holes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If conventional welding and machining methods are used to repair tip pockets, then the original shape and configuration can be restored, but the repair process becomes time-consuming and expensive

Engineering Contradiction:

Improverestoration of original tip pocket geometryVSAvoidrepair time

Core Design Contradiction:

Manufacturing precisionVSLoss of time

Solution Approach 1:

The patent replaces conventional mechanical welding and machining operations with electrical discharge machining (EDM). The EDM process uses controlled electrical discharges to erode material precisely, eliminating the need for welding followed by extensive machining. This substitution maintains geometric precision while dramatically reducing repair time and complexity

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The repair tool is designed as a precise copy or replica of the original tip pocket geometry. By creating a tool that mirrors the intended final shape, the EDM process can directly reproduce the original configuration in a single operation, avoiding multiple iterative machining steps required by conventional methods

Inventive Principle:

Principle #26Copying

2Manufacturing precision

If conventional welding and machining methods are used to repair tip pockets, then the original shape and configuration can be restored, but the repair expense increases

Engineering Contradiction:

Improverestoration of original tip pocket geometryVSAvoidrepair cost

Core Design Contradiction:

Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The patent replaces conventional mechanical welding and machining operations with electrical discharge machining (EDM). The EDM process uses controlled electrical discharges to erode material precisely, eliminating the need for welding followed by extensive machining. This substitution maintains geometric precision while dramatically reducing repair time and complexity

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The repair tool is designed as a precise copy or replica of the original tip pocket geometry. By creating a tool that mirrors the intended final shape, the EDM process can directly reproduce the original configuration in a single operation, avoiding multiple iterative machining steps required by conventional methods

Inventive Principle:

Principle #26Copying

3Manufacturing precision

If laser melting or machining is used to reopen cooling holes, then the holes can be restored to original configuration, but the process becomes more complex and time-consuming

Engineering Contradiction:

Improverestoration of cooling hole geometryVSAvoidrepair process complexity

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent combines the repair of the tip pocket cavity and the cooling holes into a single integrated EDM operation. The repair tool is designed with features that simultaneously restore both the external pocket geometry and the internal cooling hole structures, eliminating the need for separate laser melting or machining operations

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The patent replaces conventional mechanical welding and machining operations with electrical discharge machining (EDM). The EDM process uses controlled electrical discharges to erode material precisely, eliminating the need for welding followed by extensive machining. This substitution maintains geometric precision while dramatically reducing repair time and complexity

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

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 solution significantly reduces the time and expense associated with repairing gas turbine engine blades by efficiently restoring the original geometry of tip pockets and holes, enhancing the blade's performance and longevity.

Implementation Method 1

A method for repairing a gas turbine engine blade tip may comprise translating the repair tool in the z direction into the partially repaired pocket. The repair tool may be utilized in an electrical discharge machining process

Methodology Applied

Scientific EffectElectrical discharge machining: Electrical Discharge Machining

Data Source

PatentUS10376998B2Methods and tools for use in repairing gas engine turbine blades

Publication Date: 2019.08.13 RTX CORP

AI summary

A repair tool and repair method for restoring gas turbine engine blade tips to a predetermined configuration is provided. The repair tool is an electrode that includes a tool body and a number of pins. The repair tool can be used to repair turbine blade tips through an electrical discharge machining process, such as a ram- or sink-type electrical discharge machining process.