Hydraulic Actuator Flow Balancing for Synchronized Control Surfaces

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Solution Overview

Problem

Multi-actuation systems in gas turbine engines face synchronization issues due to unequal force resistance among actuators, leading to errors and reduced engine efficiency.

Innovation Solution

An actuation assembly with a flow control device that balances fluid flow rates between actuators using a passive flow control device with a movable valve body and biasing members to maintain synchronization.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a single electrohydraulic servo valve provides hydraulic flow to all actuators, then device complexity is reduced, but synchronization accuracy deteriorates due to unequal force resistance among actuators

Engineering Contradiction:
Improvenumber of control valvesVSAvoidsynchronization accuracy
Core Design Contradiction:
Device complexityVSManufacturing precision

Solution Approach 1:

The patent divides the single control valve into multiple control valves, with each valve dedicated to controlling a specific actuator. This segmentation allows independent control of each actuator's fluid flow rate, enabling precise synchronization compensation without increasing overall system complexity excessively. Each control valve can be tuned to account for the specific force resistance characteristics of its associated actuator.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent modifies the flow rate parameters supplied to each actuator by introducing flow control devices that adjust the fluid flow characteristics. By changing the flow rate parameters individually for each actuator based on their force resistance characteristics, the system achieves synchronized movement despite differences in actuator loading conditions.

Inventive Principle:
Principle #35Parameter changes

2Manufacturing precision

If tight kinematics are used to maintain actuator accuracy, then synchronization is improved, but the system becomes sensitive to force resistance variations causing actuators to fall out of sync

Engineering Contradiction:
Improveactuator synchronizationVSAvoidsynchronization stability
Core Design Contradiction:
Manufacturing precisionVSReliability

Solution Approach 1:

The patent implements a feedback mechanism where the control valves monitor and adjust the fluid flow rate to each actuator based on actual actuator performance. This feedback loop compensates for force resistance variations in real-time, maintaining synchronization stability without requiring extremely tight kinematic tolerances that would make the system sensitive to variations.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system dynamically adjusts flow rate parameters to each actuator based on their individual force resistance characteristics. By changing these parameters adaptively rather than relying on fixed kinematic relationships, the system maintains reliable synchronization even when actuators experience varying loads.

Inventive Principle:
Principle #35Parameter changes

3Power

If actuators experience unequal force resistance, then individual actuator performance may be maintained, but overall multi-actuation system accuracy deteriorates due to skewing of control surfaces

Engineering Contradiction:
Improveindividual actuator capabilityVSAvoidcontrol surface accuracy
Core Design Contradiction:
PowerVSManufacturing precision

Solution Approach 1:

The patent applies local quality by providing each actuator with its own control valve and flow control device, allowing individualized adjustment of fluid flow characteristics. This local control enables each actuator to operate at its optimal performance level while compensating for local force resistance variations, thereby maintaining overall control surface accuracy despite differences in individual actuator conditions.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The system changes the fluid flow rate parameters individually for each actuator based on their specific force resistance characteristics. By adjusting these parameters locally at each actuator rather than using a uniform approach, the system maintains both individual actuator power capability and overall control surface accuracy.

Inventive Principle:
Principle #35Parameter changes

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

Maintains synchronization among actuators, preventing skewing of control surfaces and enhancing engine performance by equalizing fluid flow rates.

Implementation Method 1

A flow control device fluidly connected to the first actuator and the second actuator is operable to balance a flow rate of a fluid at the first actuator with the flow rate of the fluid at the second actuator

Methodology Applied
Scientific EffectPressure differential: Pressure Gradient

Implementation Method 2

at least one biasing member operable to bias the valve body to a neutral position

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP4592534A1Rate matching hydraulic actuators on common control manifold
Publication Date: 2025.07.30 HAMILTON SUNDSTRAND CORP
  • EP4592534A1 patent drawingFigure 1
  • EP4592534A1 patent drawingFigure 2
  • EP4592534A1 patent drawingFigure 3

AI summary

An actuation assembly includes a control valve (46), a first actuator (48a) and a second actuator (48b) fluidly connected to the control valve (46) via plumbing. The first actuator (48a) has a first extend port and the second actuator (48b) having a second extend port. A flow control device fluidly connected to the first actuator (48a) and the second actuator (48b) is operable to balance a flow rate of a fluid at the first actuator (48a) with the flow rate of the fluid at the second actuator (48b). The flow control device is arranged within the plumbing, at a position between the control valve (46) and the first extend port and the second extend port.