Multi-Surface Accessory Gearbox Layout for Space and Temperature Fit

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Solution Overview

Problem

The variability in size and temperature requirements of accessory gearbox components in gas turbine engines poses challenges in fitting and assembling the gearbox between the engine core and core nacelle, leading to difficulties in space utilization and temperature management.

Innovation Solution

The gearbox design incorporates multiple mounting surfaces oriented both axially and radially, allowing for flexible positioning of components in areas with more space and cooler temperatures, increasing assembly flexibility and accommodating components of varying lengths and temperature needs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If accessory gearbox components are fitted between the engine core and core nacelle, then the gearbox can be integrated into the engine assembly, but the variability in component sizes and temperature requirements makes it difficult to find suitable mounting positions

Engineering Contradiction:
Improveadaptability to different component sizes and temperature requirementsVSAvoidcomplexity of fitting and assembling the gearbox
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent introduces multiple mounting surfaces oriented in different directions (axially and radially) on the gearbox housing. This multi-dimensional mounting approach allows components to be positioned according to their specific space and temperature requirements, resolving the contradiction between adaptability and assembly complexity.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Ease of operation

If multiple mounting surfaces are provided on the gearbox, then assembly flexibility is improved and components can be optimally positioned, but the gearbox structure becomes more complex

Engineering Contradiction:
Improveease of assembly and component positioningVSAvoidcomplexity of gearbox structure with multiple mounting surfaces
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The gearbox housing is designed with multiple mounting surfaces that serve universal mounting functions for various accessory components. These surfaces can accommodate different component types (generators, pumps, starters) with varying size and temperature requirements, achieving ease of assembly while maintaining a relatively simple overall structure through multi-functionality.

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

Data Source

PatentEP3578781B1Multiple mounting surface gearbox
Publication Date: 2021.12.01 RTX CORP
  • EP3578781B1 patent drawingFigure 1
  • EP3578781B1 patent drawingFigure 2A~2B
  • EP3578781B1 patent drawingFigure 3A~3B

AI summary

A gearbox (70) for a gas turbine engine (20) may comprise a first gear housing (120). A second gear housing (124) may be located proximate a first end (220) of the first gear housing (120) and may extend axially from the first gear housing (120). A third gear housing (128) may be located proximate a second end (221) of the first gear housing (120) and may extend axially from the first gear housing (120). A fourth gear housing (132) may extend circumferentially between second gear housing (124) and the third gear housing (128).