Thrust Reverser Actuation Linkage Layout for Tight Aircraft Packaging

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Solution Overview

Problem

Existing actuation systems for thrust reversers in aircraft propulsion systems face challenges due to space and packaging constraints, necessitating an improved design that can efficiently manage the movement of components while optimizing space utilization.

Innovation Solution

An actuation system comprising actuators, linkage systems, and gearboxes that include cross-over and side linkage shafts, allowing for synchronized movement of thrust reverser components, with flexible shafts and gearboxes that enable torque transfer and avoid obstacles, while maintaining synchronization among actuators.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of moving object

If traditional linkage systems are used for thrust reverser actuation, then the system can achieve basic movement functionality, but the space requirements and packaging complexity increase

Engineering Contradiction:
Improvespace utilizationVSAvoidpackaging complexity
Core Design Contradiction:
Volume of moving objectVSDevice complexity

Solution Approach 1:

The patent implements nesting by placing the cross-over shaft within the gearbox structure, and positioning linkage shafts to pass through or alongside other components. The first and second linkage shafts are arranged to operate within the confined space defined by the gearbox housing and other mechanical components, effectively nesting multiple moving elements within a compact volume.

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

The patent utilizes three-dimensional spatial arrangement by offsetting the first and second linkage shafts axially and radially, and positioning the cross-over shaft to transfer torque between different planes. This multi-dimensional arrangement allows the linkage system to achieve complex movement patterns while maintaining a compact footprint.

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

2Reliability

If multiple linkage shafts are used to synchronize actuator movement, then synchronized operation is achieved, but the system complexity and number of components increase

Engineering Contradiction:
ImprovesynchronizationVSAvoidnumber of components
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent merges the functions of multiple linkage shafts with the gearbox structure. The first and second linkage shafts are integrated with the gearbox housing, and the cross-over shaft is positioned to engage with both shafts simultaneously. This merging reduces the number of separate components while maintaining the synchronization function.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The cross-over shaft acts as an intermediary element that transfers torque between the first and second linkage shafts. This intermediary mechanism ensures synchronized operation of the actuators without requiring direct mechanical coupling between all components, thereby simplifying the overall system architecture.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Adaptability or versatility

If flexible shafts and gearboxes are used to avoid obstacles, then the system can navigate complex spatial constraints, but manufacturing complexity increases

Engineering Contradiction:
Improvespatial adaptabilityVSAvoidmanufacturing complexity
Core Design Contradiction:
Adaptability or versatilityVSEase of manufacture

Solution Approach 1:

The patent employs dynamic spatial arrangement where the linkage shafts and cross-over shaft are positioned to flexibly navigate around obstacles such as the turbine engine and nacelle structures. The shafts are arranged with appropriate clearances and angular orientations that allow for thermal expansion, manufacturing tolerances, and assembly variations while maintaining functional clearance from obstacles.

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP3951155B1Actuation system for a thrust reverser of an aircraft propulsion system
Publication Date: 2025.07.16 ROHR INC
  • EP3951155B1 patent drawingFigure 1
  • EP3951155B1 patent drawingFigure 2
  • EP3951155B1 patent drawingFigure 3

AI summary

An assembly (66) is provided for an aircraft propulsion system (20). This assembly (66) includes a first actuator (68), a second actuator (68) and a linkage system (70, 72). The linkage system (70, 72) is configured to transfer torque between the first actuator (68) and the second actuator (68). The linkage system (70, 72) includes a first linkage shaft (90), a second linkage shaft (90) and a gearbox (92). The first linkage shaft (90) has a first centerline (94). The second linkage shaft (90) has a second centerline (94) offset from the first centerline (94). The gearbox (92) is coupled to and is between the first linkage shaft (90) and the second linkage shaft (90).