Clutched Aircraft Actuation Drive for Jam Load Isolation

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Solution Overview

Problem

Aircraft actuation systems face issues with jamming, leading to excessive loads that necessitate heavier structural components to withstand these loads, resulting in weight penalties.

Innovation Solution

An actuation system with a clutch that disengages the power drive unit from actuators upon sensing abnormal load conditions, accompanied by a brake to prevent uncontrolled movement, using sensors to detect jams and trigger disengagement.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If the structure is sized to resist excessive loading from jammed components, then the system strength is improved, but the aircraft weight increases

Engineering Contradiction:
Improvesystem strengthVSAvoidaircraft weight
Core Design Contradiction:
StrengthVSWeight of moving object

Solution Approach 1:

The clutch is pre-configured to automatically disengage when abnormal load conditions are detected, preventing excessive loads from developing in the first place. This preliminary protective action eliminates the need to design structures to withstand worst-case jamming scenarios, thereby reducing weight while maintaining adequate strength for normal operation.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The clutch acts as an intermediary component between the power drive unit and the actuators. When a jam is detected, the clutch disengages to interrupt the torque transmission, serving as a protective mediator that prevents excessive loads from reaching the actuators and structure, thus avoiding the need for oversized structural components.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If mechanical torque limiters are used to prevent excessive loads, then the system reliability is improved, but the device complexity increases

Engineering Contradiction:
Improvesystem reliabilityVSAvoiddevice complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent replaces mechanical torque limiters with an electronically controlled clutch system. Sensors detect abnormal load conditions and send signals to a control unit, which then actuates the clutch to disengage. This substitution of mechanical limiting devices with an electronic control system reduces mechanical complexity while maintaining or improving reliability through more precise and adjustable protection.

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

Solution Approach 2:

The system incorporates sensors that continuously monitor load conditions and provide feedback to a control unit. When abnormal loads are detected, the control unit responds by actuating the clutch. This feedback loop provides intelligent, adaptive protection that replaces simple mechanical torque limiters with a more sophisticated but less mechanically complex electronic control system.

Inventive Principle:
Principle #23Feedback

3Reliability

If the clutch disengages rapidly upon detecting abnormal load, then the system protection is improved, but the loss of time for system response occurs

Engineering Contradiction:
Improvesystem protectionVSAvoidsystem response time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The clutch control system is pre-programmed with disengagement criteria and thresholds. When sensor readings indicate abnormal load conditions, the control unit immediately triggers clutch disengagement without delay for analysis or decision-making. This preliminary preparation of the control logic enables rapid response that minimizes time loss while providing immediate system protection.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP3795467B1Actuation system
Publication Date: 2025.07.30 GOODRICH ACTUATION SYST
  • EP3795467B1 patent drawingFigure 1
  • EP3795467B1 patent drawingFigure 2
  • EP3795467B1 patent drawingFigure 3

AI summary

An actuation system (2) comprises a plurality of actuators (10), a common power drive unit (12) for driving the actuators (10) and a transmission line (14) transmitting drive from the common drive unit (14) to the plurality of actuators (10). A clutch (24) is arranged in the transmission line (14) between the power drive unit (12) and the plurality of actuators (10) for selectively disconnecting the power drive unit (12) from the plurality of actuators (4). At least one sensor (26) is provided for sensing an abnormal load condition in the actuation system (2). The at least one sensor (26) is operatively coupled to a clutch control (28) which is configured such that when the at least one sensor (26) senses an abnormal load condition, the clutch control (28) is operative to disengage the clutch (24) so as to disconnect the power drive unit (12) from the plurality of actuators (10). A brake (20) is operative to brake the actuators (10) upon disengagement of the clutch (24).