Redundant Hydraulic Control Valve Spool Coupling for Force Fight Mitigation
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Solution Overview
Problem
Hydraulic actuators in rotorcraft with redundant fluid sources often experience force fights due to manufacturing variability and uncoordinated fluid flow regulation, leading to inefficiencies and the need for additional structural margin and sensors.
Innovation Solution
A control valve assembly with a tandem pin mechanism that synchronizes the translation of spools and flanges between redundant control valves, using a solenoid or linear motor to maintain engagement or disengagement, ensuring coordinated fluid flow and preventing force fights.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If redundant hydraulic systems are used to improve reliability, then system reliability is improved, but force fights develop due to uncoordinated flow regulation
Solution Approach 1:
The patent merges the control functions of two redundant hydraulic systems into a single integrated control valve assembly. The spools from both systems are positioned within a common valve body and work together to regulate flow to the actuator, ensuring coordinated operation and eliminating force fights while maintaining redundancy for reliability.
Solution Approach 2:
The control valve assembly acts as an intermediary between the two redundant hydraulic systems and the actuator. It coordinates the flow regulation from both systems, preventing direct conflict between them by providing a unified control mechanism that manages their interaction.
2Object-generated harmful factors
If additional sensors and control algorithms are added to manage force fight magnitude, then force fight is mitigated, but device complexity increases
Solution Approach 1:
The patent extracts the force fight mitigation function from the overall system and incorporates it directly into the control valve assembly structure. By integrating the coordination mechanism within the valve itself, the need for external sensors and complex control algorithms is eliminated, reducing device complexity while still managing force fight.
3Object-generated harmful factors
If manufacturing variability is reduced to improve spool coordination, then force fight is reduced, but manufacturing precision requirements increase
Solution Approach 1:
By merging the spools into a single integrated assembly within the valve body, the patent ensures that both spools are manufactured and positioned together as a coordinated unit. This integrated approach maintains consistent spacing and alignment between spools, reducing force fight caused by manufacturing variability without requiring extremely tight individual tolerances.
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
The solution effectively mitigates force fights, enhances reliability, and reduces the need for additional sensors and structural margin, providing lightweight and redundant hydraulic flight control actuators with improved safety and reduced risk.
Implementation Method 1
A solenoid or linear motor can be coupled to the tandem pin to displace the tandem pin along the pin axis
Implementation Method 2
A solenoid or linear motor can be coupled to the tandem pin to displace the tandem pin along the pin axis
Implementation Method 3
A seal can be disposed between the flange and the spool to fluidly isolate hydraulic fluid within the valve body from the environment external to the valve body
Implementation Method 4
A rail can be fixed relative to the valve body. The rail can extend along the translation axis. The rail can be offset laterally relative to the translation axis
Data Source
AI summary
A control valve for a multi-stage hydraulic actuator includes a valve body defining a translation axis, a spool disposed within the valve body and movable along the translation axis, and a flange. The flange is fixed relative to the spool and has an aperture disposed externally of the valve body to removably fix the spool to a spool of a redundant control valve independently connected to the multi-stage hydraulic actuator for mitigating force fights between actuators coupled to the control valve.