Rotary Control Valve Bypass Mechanism for Actuator Jamming
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Solution Overview
Problem
Existing actuator control systems lack a redundant mechanism to maintain operation when rotary valves become jammed, as they require physical access for maintenance and do not allow remote switching to a by-pass mode, which can lead to system failure.
Innovation Solution
A pair of synchronously driven rotary control valves with a by-pass mode mechanism, coupled to a pilot control or flight control computer, allowing remote activation of the by-pass mode through hydraulic or mechanical couplings, and a latch system to facilitate communication between control and pressure lines, enabling continued operation even if one valve jams.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a by-pass valve arrangement is provided to permit continued operation when a valve becomes jammed, then system reliability is improved, but device complexity increases
Solution Approach 1:
The by-pass function is merged into the existing rotary control valve structure itself, rather than being a separate external arrangement. The valve body incorporates internal by-pass passages that can be activated through the normal valve operation mechanism, combining the primary control function and by-pass function into a single integrated component.
Solution Approach 2:
The rotary control valve is designed to perform multiple functions: normal flow control in active mode, and by-pass flow control in bypass mode. The same valve structure and actuation mechanism serve both the primary control function and the redundancy function, allowing one component to fulfill multiple roles in the system.
2Reliability
If a test piston is provided to activate by-pass mode during maintenance, then reliability is improved, but ease of operation deteriorates
Solution Approach 1:
The system provides self-service capability through the flight control computer automatically detecting valve jamming conditions and activating the by-pass mode without requiring manual intervention. The FCC monitors valve operation parameters and autonomously switches to by-pass mode when abnormal conditions are detected, eliminating the need for pilot action during normal operation.
Solution Approach 2:
The flight control computer acts as an intermediary between the valve system and the pilot. Instead of the pilot directly operating the valve or test piston, the FCC receives input from sensors monitoring valve operation and automatically actuates the by-pass mechanism when needed, serving as an intelligent mediator that simplifies the interface for the end user.
3Ease of operation
If remote switching capability is added to activate by-pass mode under pilot or FCC control, then ease of operation is improved, but device complexity increases
Solution Approach 1:
The manual mechanical test piston operation is replaced with an electronically controlled actuation system. The flight control computer uses electrical signals to control solenoid valves or direct-acting actuators that switch the by-pass mode, replacing the need for physical manual intervention with an automated electronic control system.
Solution Approach 2:
The by-pass actuation mechanism uses pneumatic or hydraulic pressure to switch valve positions remotely. Pressurized fluid is directed through control lines to actuate the by-pass mechanism from a distance, allowing the pilot or FCC to control valve mode changes without physical proximity to the valve assembly.
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
Enables continued operation of the actuator in a degraded mode by allowing remote switching to a by-pass mode, reducing system weight and complexity while maintaining safety and functionality, even in the event of valve jamming, and allows for simulated jam scenarios for pilot training.
Implementation Method 1
The mechanism may comprise a hydraulic piston operable by the FCC or pilot control to put one or both of the rotary control valves into by-pass mode
Implementation Method 2
The latch element cooperating with the formation and being urged into the recess to resist angular movement of the second spool
Data Source
AI summary
An actuator control arrangement is provided comprising a pair of rotary control valves used in combination to control the operation of an actuator. The rotary control valves are driven synchronously through a hydraulic or mechanical coupling. Each rotary control valve has a by-pass mode which activates in the event of a jam. In addition each rotary control valve has a mechanism for activating the by-pass mode absent any jam. The actuator control arrangement further comprises a circuit coupling a pilot control and/or a flight control computer (FCC) to one or both of the mechanisms for remotely switching the rotary control valve(s) from an active mode to a by-pass mode under control of a pilot or FCC.