Integrated Hydraulic Valve for Flight Actuator Failure Bypass
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Solution Overview
Problem
Existing flight control systems for aircraft lack redundancy and fail to efficiently manage hydraulic actuator failures, leading to potential damage and reduced control surface functionality.
Innovation Solution
An integrated three-function valve (ITFV) that combines differential pressure sensing, pressure relief, and bypass functions, featuring an inner spool within an intermediate spool, to manage pressure differentials and ensure actuator redundancy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If multiple separate valves are used for differential pressure sensing, pressure relief, and bypass functions, then each function can be independently optimized, but the device complexity and number of components increases
Solution Approach 1:
The patent combines three separate hydraulic valve functions (differential pressure sensing, pressure relief, and bypass) into a single integrated valve assembly. The inner spool handles differential pressure sensing and bypass, while the outer spool handles pressure relief, allowing all three functions to be performed by one compact unit rather than three separate valves, thereby reducing system complexity while maintaining reliability
Solution Approach 2:
The integrated valve assembly is designed to perform multiple functions simultaneously: the inner spool provides both differential pressure sensing and bypass capabilities, while the outer spool provides pressure relief. This multi-functional design eliminates the need for separate dedicated valves for each function, reducing the overall number of components in the hydraulic system
2Device complexity
If a single integrated valve is used for all three functions, then device complexity is reduced, but the reliability may be compromised if one function fails
Solution Approach 1:
The integrated valve is segmented into two independent spool assemblies: an inner spool for differential pressure sensing and bypass functions, and an outer spool for pressure relief functions. This segmentation allows each spool to operate independently, so if one spool fails, the other can continue to provide its designated function, maintaining system reliability while keeping the overall device compact
Solution Approach 2:
The valve body acts as an intermediary structure that houses both the inner and outer spools, providing independent flow paths and pressure chambers for each function. This intermediary structure ensures that failures in one spool do not propagate to the other, maintaining functional redundancy within the integrated assembly
3Ease of operation
If conventional hydraulic systems without integrated valves are used, then system simplicity is maintained, but the ability to automatically bypass failed actuators and balance forces is lost
Solution Approach 1:
The integrated valve assembly is designed to automatically respond to actuator failures and pressure imbalances without external intervention. The inner spool automatically senses differential pressure and opens bypass paths when actuators fail, while the outer spool automatically relieves excessive pressure, allowing the system to self-correct and maintain operation without pilot assistance
Solution Approach 2:
The differential pressure sensing function of the inner spool provides continuous feedback on actuator performance. When pressure differentials indicate actuator failure or imbalance, the spool automatically adjusts the bypass flow to correct the condition, creating a closed-loop feedback system that maintains optimal operation without external control
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 ITFV provides failsafe operation by automatically bypassing failed actuators, balancing actuator forces, and preventing damage to flight control surfaces, ensuring continuous control surface functionality.
Implementation Method 1
an inner spool actuable in a first direction and a second direction responsive to a pressure differential acting across the inner spool
Implementation Method 2
an intermediate spool actuable in the first direction and second direction between an active position and a bypass position; wherein the ITFV comprises an activation chamber for receiving hydraulic fluid, and a bypass spring, wherein the intermediate spool is actuable based upon the forces from the bypass spring and hydraulic fluid in the activation chamber
Implementation Method 3
the intermediate spool is actuable based upon the forces from the bypass spring and hydraulic fluid in the activation chamber
Implementation Method 4
a hydraulic system for a flight control surface is provided, comprising: the ITFV; a hydraulic actuator comprising a first actuator chamber and a second actuator chamber, wherein the inner spool of the ITFV is actuable based upon a pressure difference between the first actuator chamber and the second actuator chamber
Data Source
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AI summary
An integrated three function valve (ITFV) for an actuator of a flight control surface, the ITFV comprising: an inner spool actuable in a first direction and a second direction responsive to a pressure differential acting across the inner spool; an intermediate spool actuable in the first direction and second direction between an active position and a bypass position; wherein the inner spool is located within the intermediate spool.