Pneumatic Shaft Disconnect Mechanism for Remote Power Train Separation

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Solution Overview

Problem

Existing mechanical disconnect mechanisms for power trains in aircraft are inadequate for efficient and remote-controlled disconnection of rotating shafts, particularly in scenarios requiring maintenance or emergency disconnects.

Innovation Solution

A system comprising a first shaft assembly and a second shaft splined together, with a pneumatic piston system and solenoid valves for remote actuation, allowing the shafts to be axially shifted between coupled and decoupled positions for independent rotation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If conventional mechanical disconnect mechanisms are used, then the structure is simple, but the ease of operation for remote-controlled disconnection is poor

Engineering Contradiction:
Improveremote-controlled disconnectionVSAvoidpneumatic system complexity
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The patent replaces conventional manual mechanical operation with a pneumatic actuation system. A pneumatic cylinder with piston receives pressurized air to generate linear motion, which is then converted to rotational motion of the disconnect shaft through a rack-and-pinion mechanism. This substitution enables remote-controlled operation while maintaining mechanical reliability.

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

Solution Approach 2:

The patent employs a pneumatic system to actuate the disconnect mechanism. Pressurized air is supplied to a pneumatic cylinder, causing the piston to move linearly. This pneumatic actuation provides controlled, reliable motion for engaging and disengaging the splined shafts, enabling remote operation without direct mechanical linkage.

Inventive Principle:
Principle #29Pneumatics and hydraulics

2Adaptability or versatility

If the shafts are mechanically connected for common rotation, then the power transmission is efficient, but the adaptability for independent rotation during maintenance or emergencies is poor

Engineering Contradiction:
Improveindependent rotation capabilityVSAvoiddisconnect mechanism complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent creates a dynamic disconnect mechanism where two splined shafts can transition between coupled and uncoupled states. When coupled, the shafts rotate together for efficient power transmission. When uncoupled, they can rotate independently to enable maintenance operations or emergency isolation. The pneumatic actuation system enables this dynamic state change.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent segments the power transmission system into two independently rotatable shafts that can be mechanically coupled or decoupled. The first splined shaft and second splined shaft are separated by the disconnect mechanism, allowing each shaft to be independently maintained or operated while providing adaptability for different operational scenarios.

Inventive Principle:
Principle #1Segmentation

3Ease of repair

If manual actuation is added to pneumatic system, then the ease of repair is improved, but the device complexity increases

Engineering Contradiction:
Improvemanual actuation capabilityVSAvoidactuation system complexity
Core Design Contradiction:
Ease of repairVSDevice complexity

Solution Approach 1:

The patent designs the actuation system with multi-functionality, allowing it to operate in two modes: automated pneumatic actuation for normal operations and manual actuation for maintenance or emergency situations. The disconnect shaft can be manually rotated to engage or disengage the splined connection, providing versatility and ease of repair without requiring specialized tools or procedures.

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

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

Enables efficient, remote-controlled, and cost-effective mechanical disconnection of power train shafts, reducing interference and adding manual actuation functionality, which is particularly beneficial for flight-critical systems.

Implementation Method 1

a piston in a pneumatic chamber configured so that pressurizing a first compartment of the pneumatic chamber on a first side of the pneumatic piston actuates the first shaft assembly axially

Methodology Applied
Scientific EffectPneumatic pressure: Pressurisation

Implementation Method 2

A first solenoid valve can be in fluid communication with the first compartment for selectively pressuring the first compartment to drive the piston

Methodology Applied
Scientific EffectSolenoid actuation: Solenoid

Data Source

PatentEP4563838A1Pneumatic and manually driven disconnect mechanism for mechanically separating a power train
Publication Date: 2025.06.04 HAMILTON SUNDSTRAND CORP
  • EP4563838A1 patent drawingFigure 1
  • EP4563838A1 patent drawingFigure 2
  • EP4563838A1 patent drawingFigure 3

AI summary

A system includes a first shaft assembly (102) and a second shaft (104) splined to the first shaft assembly with the first shaft in a first axial position for common rotation of the first shaft assembly and the second shaft. In a second axial position of the first shaft assembly, the first shaft assembly and the second shaft are separated for disconnecting them from common rotation. The first shaft assembly includes a piston (128) in a pneumatic chamber (130) configured so that pressurizing a first compartment (134) of the pneumatic chamber on a first side of the pneumatic piston actuates the first shaft assembly axially toward the first position, and pressurizing a second compartment (132) of the pneumatic chamber on a second side of the piston opposite the first side of the piston actuates the first shaft assembly axially toward the second position.