End Region Inspection Module Using an Air-Gap Crawler

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Solution Overview

Problem

Existing methods for inspecting generators, electric motors, and turbomachines require disassembly and removal of the rotor, which is costly, time-consuming, and risky, and do not provide complete or safe inspections.

Innovation Solution

A robotic crawler system that can be inserted through the radial air gap between the core iron and retaining ring of a machine, allowing for in situ inspection of the rotor and stator core, equipped with a visual inspection module and extension member for inspecting hard-to-reach end regions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If complete disassembly and rotor removal is performed for inspection, then inspection completeness is improved, but time consumption and cost increase

Engineering Contradiction:
Improveinspection completenessVSAvoidtime consumption
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The inspection system is divided into modular components: a robotic crawler for navigation, an extendible mast for reaching different depths, and interchangeable inspection tools. This segmentation allows the system to perform complete inspections without full disassembly by accessing different regions through the air gap.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The robotic crawler acts as an intermediary device that passes through the air gap between rotor and stator to reach inspection areas. This mediator enables inspection of internal components without requiring removal of the rotor, thus reducing time while maintaining completeness.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Measurement precision

If complete disassembly and rotor removal is performed for inspection, then inspection completeness is improved, but cost increases

Engineering Contradiction:
Improveinspection completenessVSAvoidcost
Core Design Contradiction:
Measurement precisionVSEase of manufacture

Solution Approach 1:

The robotic crawler is equipped with its own power source, navigation capabilities, and inspection tools, enabling it to autonomously perform inspection tasks within the air gap. This self-service capability eliminates the need for expensive disassembly operations while achieving complete inspection coverage.

Inventive Principle:
Principle #25Self-service

3Measurement precision

If rotor removal is performed for inspection, then inspection completeness is improved, but safety risks increase

Engineering Contradiction:
Improveinspection completenessVSAvoidsafety risks
Core Design Contradiction:
Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The robotic crawler serves as a safe intermediary that can be inserted through the air gap to inspect rotor and stator components without physical removal. This eliminates safety hazards associated with rotor handling while maintaining inspection completeness through extended mast and various inspection tools.

Inventive Principle:
Principle #24Intermediary (Mediator)

4Device complexity

If traditional inspection methods are used, then equipment complexity is reduced, but inspection completeness deteriorates

Engineering Contradiction:
Improveequipment complexityVSAvoidinspection completeness
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The robotic crawler is designed as a universal inspection platform that can perform multiple functions: navigation through the air gap, extension to reach different depths, and accommodation of various inspection tools (visual, electrical, mechanical). This multi-functionality achieves complete inspection without proportionally increasing equipment complexity.

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

5Measurement precision

If robotic crawler with extension member is used for end region inspection, then inspection completeness is improved, but device complexity increases

Engineering Contradiction:
Improveend region inspection capabilityVSAvoiddevice complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The inspection system uses a nested structure where the mast can be extended from the crawler body, and inspection tools are nested within the mast. This nested doll approach enables end region inspection capability while minimizing device complexity by collapsing the structure when not in use.

Inventive Principle:
Principle #7Nested doll (Nesting)

Data Source

PatentEP3655763B1End region inspection module and method for in SITU gap inspection robot system
Publication Date: 2025.10.22 GENERAL ELECTRIC TECH GMBH
  • EP3655763B1 patent drawingFigure 1
  • EP3655763B1 patent drawingFigure 2~3
  • EP3655763B1 patent drawingFigure 4~5

AI summary

This disclosure provides systems and methods for in situ gap inspection in a machine, such as a generator, an electric motor, or a turbomachine, with an end region. A robotic crawler is configured to navigate an annular gap of the machine. A visual inspection module is connected to the robotic crawler and includes an extension member for extending a camera into the end region to collect visual inspection data.