Aircraft Drive Line Shaft With Front-Access Connecting Ring

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing aircraft turbine engine drive line shafts require complete disassembly for maintenance due to inaccessible connecting rings, which is time-consuming and complex, especially when the reduction gearbox shaft has a reduced diameter.

Innovation Solution

A main shaft with a captive connecting ring system, featuring front and rear retaining members and a connecting ring that can be accessed and rotated from the front, allowing disassembly and assembly of drive line shafts without external encumbrance, even with reduced access diameters.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the connecting ring is positioned downstream to connect the compressor shaft and turbine shaft, then the drive line structure is secure, but the connecting ring becomes inaccessible for maintenance without complete disassembly of the drive line

Engineering Contradiction:

Improvedrive line structural integrityVSAvoidaccessibility of connecting ring for maintenance

Core Design Contradiction:

ReliabilityVSEase of operation

Solution Approach 1:

The drive line is segmented into modular components (reduction gearbox shaft, compressor shaft, turbine shaft) that can be independently accessed. The connecting ring is designed as a separate, removable component that can be manipulated through the upstream end, allowing maintenance without complete disassembly of the entire drive line assembly.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The connecting ring is nested within the hollow interior of the compressor shaft, allowing it to be accessed and manipulated from the upstream end through the hollow passage. This nesting arrangement enables maintenance personnel to reach the connecting ring without external access at the downstream position.

Inventive Principle:

Principle #7Nested doll (Nesting)

2Volume of moving object

If the reduction gearbox shaft diameter is reduced to minimize radial space, then the engine compactness is improved, but the shaft becomes too narrow to allow passage of tools for connecting ring manipulation

Engineering Contradiction:

Improveradial space occupied by reduction gearbox shaftVSAvoidtool accessibility through shaft for connecting ring manipulation

Core Design Contradiction:

Volume of moving objectVSEase of operation

Solution Approach 1:

The connecting ring manipulation is moved from external downstream access to internal upstream access through the hollow passage of the compressor shaft. This dimensional shift allows tool access through the length of the shaft rather than requiring radial space at the downstream end, enabling the reduction gearbox shaft to have a smaller diameter.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

3Ease of repair

If complete disassembly of the drive line is performed to access the connecting ring, then the connecting ring can be removed for maintenance, but the maintenance time and complexity increase significantly

Engineering Contradiction:

Improveability to remove connecting ring for maintenanceVSAvoidmaintenance time for drive line disassembly and reassembly

Core Design Contradiction:

Ease of repairVSLoss of time

Solution Approach 1:

The connecting ring is extracted as a separate, independently removable component from the drive line assembly. It can be unscrewed and removed through the upstream end of the compressor shaft without requiring disassembly of the reduction gearbox shaft, compressor shaft, or turbine shaft connections, significantly reducing maintenance time and complexity.

Inventive Principle:

Principle #2Taking out (Extraction)

4Loss of time

If the connecting ring is made accessible from the upstream end, then maintenance time is reduced, but the connecting ring requires additional structural features (retaining members, prison) that increase device complexity

Engineering Contradiction:

Improvemaintenance time for drive line assemblyVSAvoidstructural complexity of connecting ring system with retaining members

Core Design Contradiction:

Loss of timeVSDevice complexity

Solution Approach 1:

The compressor shaft serves multiple functions: it transmits rotational power from the turbine and simultaneously provides a hollow passage for accessing and manipulating the connecting ring from the upstream end. The retaining members and prison structure serve dual purposes of securing the connecting ring during operation and enabling its removal during maintenance without additional external mechanisms.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Data Source

PatentUS12371995B2Aircraft turbine engine drive line shaft comprising a connecting ring for disassembling the drive line

Publication Date: 2025.07.29 SAFRAN AIRCRAFT ENGINES SAS

AI summary

Disclosed is a main shaft for an aircraft turbine engine drive line extending longitudinally from front to rear along an axis and having a rear portion configured for receiving a front portion of a rear shaft by interlocking, the main shaft having: —a front retaining member and a rear retaining member together defining a prison and each having a central opening, —a connecting ring, located in the prison, having a rear end configured to be screwed to a front end of the rear shaft extending into the central opening of the rear retaining member, the connecting ring having a gripping member formed on the inner surface and accessible from a front portion of the main shaft by a tool extending via the central opening of the front retaining member.