Removable Reactivation Pack for Helicopter Turboshaft Engine Weight Reduction

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Solution Overview

Problem

Existing reactivation packs for helicopter turbine engines increase weight, leading to fuel overconsumption and performance imbalance among engines, as they are often permanently installed and not adaptable to varying mission requirements.

Innovation Solution

A removable reactivation pack with two independent reactivation devices, one for rapid and one for normal operation, allowing on-demand hybridization of turbine engines and balancing engine aging by being mountable on specific engines as needed, using reversible coupling to the gas generator shaft and featuring distinct reactivation mechanisms.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a reactivation pack is permanently installed on a turboshaft engine to enable standby mode operation, then the engine can be reactivated rapidly when needed, but the weight of the helicopter increases leading to fuel overconsumption

Engineering Contradiction:
Improveengine reactivation capabilityVSAvoidhelicopter weight
Core Design Contradiction:
ReliabilityVSWeight of moving object

Solution Approach 1:

The reactivation pack is designed to be removable rather than permanently installed, allowing the system to dynamically adapt its configuration based on mission requirements. The pack can be installed when standby mode capability is needed and removed when it is not, making the weight characteristic variable rather than fixed.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The reactivation pack is designed as a separate, modular unit that can be independently installed or removed from the turboshaft engine. This segmentation allows the helicopter to have the reactivation capability only when specifically needed, rather than carrying it permanently.

Inventive Principle:
Principle #1Segmentation

2Adaptability or versatility

If reactivation packs are permanently installed on all turboshaft engines, then all engines can operate in standby mode, but this creates performance imbalance and unnecessary weight during missions where standby is not required

Engineering Contradiction:
Improvestandby mode capabilityVSAvoidhelicopter weight
Core Design Contradiction:
Adaptability or versatilityVSWeight of moving object

Solution Approach 1:

The system allows the reactivation pack to be selectively installed on specific engines based on mission requirements. This creates a dynamic configuration where the helicopter can be adapted for standby operations only when needed, rather than permanently carrying the weight of reactivation packs on all engines.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The removable reactivation pack design provides universal adaptability - the same pack can be installed on any turboshaft engine as needed, allowing the helicopter fleet to be configured for standby operations on a per-mission basis rather than requiring all engines to have permanent standby capability.

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

3Reliability

If turboshaft engines are oversized to ensure flight in all conditions including high altitude and hot weather, then the helicopter can operate throughout the entire flight envelope, but this increases weight and fuel consumption during cruise flight

Engineering Contradiction:
Improveflight envelope coverageVSAvoidfuel consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

By enabling standby mode operation through the removable reactivation pack, the system allows one engine to be shut down during cruise flight, thereby using a smaller, less powerful engine configuration when full power is not needed. This dynamic operation reduces fuel consumption during cruise while maintaining the capability for full power operation when required.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The engine operates in alternating states of active and standby mode based on flight conditions. During cruise flight, the standby engine remains off; when additional power is needed, it can be rapidly reactivated. This periodic activation pattern reduces average fuel consumption while maintaining reliability.

Inventive Principle:
Principle #19Periodic action

4Use of energy by moving object

If one turboshaft engine is placed in standby mode to reduce fuel consumption, then specific fuel consumption improves, but the engine must be rapidly reactivated in critical situations which requires complex reactivation mechanisms

Engineering Contradiction:
Improvespecific fuel consumptionVSAvoidreactivation mechanism
Core Design Contradiction:
Use of energy by moving objectVSDevice complexity

Solution Approach 1:

The reactivation mechanism is segmented into a self-contained reactivation pack that includes all necessary components (energy storage device, coupling means, control systems). This modular segmentation simplifies the overall system architecture by isolating the complexity within a removable unit rather than integrating it throughout the engine system.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The energy storage device in the reactivation pack is pre-charged and ready to immediately provide the energy needed for rapid engine reactivation. The coupling means are pre-positioned and ready to engage with the engine's drive shaft, eliminating the need for complex real-time preparation during critical reactivation scenarios.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP3209872B1Removable pack for reactivating a turboshaft engine, architecture for a multi-engine system for propelling a helicopter, provided with such a pack, and corresponding helicopter
Publication Date: 2021.07.21 SAFRAN HELICOPTER ENGINES
  • EP3209872B1 patent drawingFigure 1~3

AI summary

The invention relates to a removable pack for reactivating a helicopter turboshaft engine (6), including a gas generator (7) provided with a drive shaft (12). Said turboshaft engine (6) is capable of operating in at least one standby mode during a stabilized flight of the helicopter. Said removable pack includes: a removable housing (30) including a housing output shaft (31); controlled means (32, 33) for rotating said housing output shaft (31), said means being a so-called means for reactivating said turboshaft engine; and mechanical means (14) for reversibly coupling said housing output shaft (31) with said shaft (12) for driving said gas generator.