Turbine Guide Vane Repair Using 3D Geometry and CNC Contouring

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Solution Overview

Problem

The manual removal of excess material from repaired turbine blades in gas turbines, particularly aircraft gas turbines, results in suboptimal shape and contour, leading to power losses, increased fuel consumption, and reduced running times due to inefficient flow conditions in the A4 cross-section.

Innovation Solution

A method involving non-contact geometry measurement, comparison with a target geometry, and automated material removal to restore the optimal flow contour, using techniques like milling and grinding, ensuring precise restoration of the turbine blade's shape for improved efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If manual material removal is used to repair turbine blades, then the repair process is simple and flexible, but the shape and contour precision deteriorates leading to suboptimal flow conditions

Engineering Contradiction:
Improverepair process simplicityVSAvoidflow contour precision
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

The patent replaces manual mechanical material removal with an automated mechanical system. A five-axis CNC milling machine with robotic positioning and automated tool changing performs material removal based on pre-calculated toolpaths from 3D scans, eliminating manual operation while achieving precise flow contour restoration.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The system uses 3D scanning to automatically capture the actual geometry of the turbine blade, compares it with the target geometry, and generates optimized toolpaths without human intervention. The automated system then executes the material removal process, making the repair process self-sufficient and eliminating manual measurement and calculation steps.

Inventive Principle:
Principle #25Self-service

2Manufacturing precision

If automated material removal is used to restore optimal flow contour, then the manufacturing precision improves, but the device complexity increases

Engineering Contradiction:
Improveflow contour precisionVSAvoidrepair system complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The system integrates multiple functions into a unified automated platform: 3D scanning for geometry capture, computational geometry processing for target comparison and toolpath generation, and five-axis CNC milling for material removal. This multi-functional integration achieves precise flow contour restoration while managing system complexity through consolidation.

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

Solution Approach 2:

The patent introduces computational geometry processing as an intermediary between scanning and material removal. This software intermediary automatically compares scanned geometry with target geometry, calculates deviations, and generates optimized toolpaths, serving as a bridge that coordinates the scanning and machining operations without requiring direct human intervention.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Loss of energy

If precise flow contour restoration is achieved in the A4 cross-section region, then the gas turbine efficiency improves and fuel consumption decreases, but the measurement and manufacturing complexity increases

Engineering Contradiction:
Improvefuel consumptionVSAvoidmeasurement and manufacturing complexity
Core Design Contradiction:
Loss of energyVSDevice complexity

Solution Approach 1:

The system applies local quality by focusing measurement and material removal precision on the critical A4 cross-section region. The 3D scanning and CNC machining processes prioritize accuracy in this specific area where flow conditions most significantly impact turbine efficiency, rather than uniformly treating the entire blade surface.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent replaces manual measurement and material removal operations with automated five-axis CNC machining guided by 3D scan data. This substitution enables precise restoration of the A4 cross-section geometry without the variability and imprecision of manual operations, directly improving flow conditions and reducing energy losses.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Data Source

PatentEP3202529B1Repair method for turbine vanes, repaired turbine vane and repair system for repairing turbine vanes
Publication Date: 2023.11.22 MTU AERO ENGINES GMBH
  • EP3202529B1 patent drawingFigure 1
  • EP3202529B1 patent drawingFigure 2
  • EP3202529B1 patent drawingFigure 3I~3III

AI summary

The invention relates to a repair method for guide vanes (10, 10') of a gas turbine, in particular an aircraft gas turbine, comprising the following steps: providing at least one guide vane (10, 10') to be serviced; acquiring the actual geometry of the guide vane (10, 10') to be serviced using at least one measurement method; comparing the actual geometry acquired by the non-contact measurement method with a predetermined target geometry (TG) for a corresponding guide vane type; calculating a target geometry (TG) for the guide vane (10, 10') to be serviced, which corresponds as closely as possible to the target geometry (TG), such that, using optimization parameters, the target geometry (TG) of the guide vane (10, 10') to be serviced is approximated at least section by section along its flow contour;Application and mechanical removal of material (22) from the guide vane (10, 10') to be serviced, such that the calculated target geometry (ZG) is produced.;