Gearbox Housing Hole Realignment Through Compensation Machining

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Gearbox assemblies for rotational equipment, such as those in aircraft propulsion systems, experience wear over time, leading to misalignment and deformation of housing components, which affects mechanical performance and efficiency, and existing replacement methods are costly and inefficient.

Innovation Solution

A gearbox repair system utilizing a controller with a processor and repair tools, including machining tools and touch probes, to identify and adjust the positions of holes in the housing components by applying compensation vectors, ensuring precise alignment and restoration of geometric characteristics.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If gearbox housing components are replaced when worn, then reliability is improved, but loss of substance increases and productivity decreases

Engineering Contradiction:
Improvegearbox assembly reliabilityVSAvoidhousing material loss
Core Design Contradiction:
ReliabilityVSLoss of substance

Solution Approach 1:

The patent applies the discarding and recovering principle by removing worn material from gearbox housing components through machining and restoring them to serviceable condition. Instead of discarding entire worn housings, the system recovers usable material by selectively removing only the worn portions and repairing the components, thereby extending their service life while maintaining reliability.

Inventive Principle:
Principle #34Discarding and recovering

2Reliability

If gearbox housing components are replaced when worn, then reliability is improved, but productivity decreases

Engineering Contradiction:
Improvegearbox assembly reliabilityVSAvoidrepair efficiency
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent applies mechanics substitution by replacing manual inspection and repair methods with an automated optical measurement and machining system. The system uses optical sensors to automatically detect hole positions, calculates compensation vectors, and controls machining operations, thereby improving repair efficiency and productivity while ensuring consistent reliability outcomes.

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

Solution Approach 2:

The repair system applies the self-service principle by enabling the gearbox housing components to essentially repair themselves through the automated process. The system automatically measures the actual positions of holes, calculates the necessary compensation vectors, and executes the machining operations without requiring extensive manual intervention, thereby improving productivity.

Inventive Principle:
Principle #25Self-service

3Device complexity

If traditional repair methods are used, then device complexity is reduced, but manufacturing precision deteriorates

Engineering Contradiction:
Improverepair system complexityVSAvoidhole position accuracy
Core Design Contradiction:
Device complexityVSManufacturing precision

Solution Approach 1:

The patent applies mechanics substitution by replacing simple manual measurement and marking methods with an automated optical measurement and CNC machining system. This substitution increases device complexity but dramatically improves manufacturing precision by automatically detecting actual hole positions and calculating precise compensation vectors for repair operations.

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

Solution Approach 2:

The repair system applies feedback by using optical sensors to measure the actual positions of holes in the gearbox housing, comparing these measurements against reference positions, and using the detected deviations to calculate compensation vectors that guide the machining process. This closed-loop feedback ensures high manufacturing precision in hole position accuracy.

Inventive Principle:
Principle #23Feedback

Data Source

PatentEP4467283A1System and method for repairing a housing for a gearbox
Publication Date: 2024.11.27 PRATT & WHITNEY CANADA CORP
  • EP4467283A1 patent drawingFigure 1
  • EP4467283A1 patent drawingFigure 2
  • EP4467283A1 patent drawingFigure 3

AI summary

A gearbox repair system (114) includes at least one repair tool (128) and a controller (124). The controller (124) is configured to control the at least one repair tool (128) to repair a gearbox housing (60) including a first housing body (66) and a second housing body (68) by: controlling the at least one repair tool (128) to repair the first housing body (66) at a first hole (104A) of the first housing body (66) by removing a first body material of the first housing body (66) at the first hole (104A), controlling the at least one repair tool (128) to identify a first actual position (144) of the first hole (104A), identifying a compensation vector (140) for the first hole (104A) based on the first actual position (144) and a first reference position (146) for the first hole (104A), and controlling the at least one repair tool (128) to repair the second housing body (68) at a second hole (104B) of the second housing body (68) by removing a second body material at the second hole (104B) such that a second actual position (158) of the second hole (104B) is offset from a second reference position (156) of the second hole (104B) by the compensation vector (140).