Variable Horn Radius Actuator for Lower-Power Flight Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Aircraft hydraulic systems face challenges in efficiently actuating flight control surfaces against varying loads due to peak hydraulic power demands, which limit performance and payload capacity.
Innovation Solution
The implementation of a control surface actuator assembly featuring a torque-generating hydraulic actuator and a variable horn radius (VHR) hydraulic actuator, which pivot relative to each other to dynamically adjust the actuator moment arm length, allowing for selective variation of torque applied to flight control surfaces without substantial reconfiguration of the hydraulic system.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If the hydraulic system operates at a fixed pressure with variable flow rate, then the actuator can provide consistent force, but significant pressure loss occurs due to metering of the flow at the actuators
Solution Approach 1:
The system dynamically adjusts the moment arm length of the actuator through a variable geometry mechanism, allowing the actuator to operate at different mechanical advantages. This enables the system to maintain required torque output while reducing peak hydraulic pressure demands, thereby minimizing pressure loss during flow metering.
Solution Approach 2:
The invention changes the geometric parameter of the moment arm length dynamically. By varying this parameter, the system adjusts the mechanical advantage of the actuator, allowing operation at lower hydraulic pressures for the same torque output, which reduces pressure loss in the hydraulic system.
2Loss of energy
If the operating pressure of the hydraulic system is variable, then pressure loss is reduced, but the pressure must be configured to correspond to the largest load encountered by any of the actuators
Solution Approach 1:
The variable moment arm mechanism allows the actuator to dynamically adjust its mechanical advantage based on the instantaneous load requirements. This enables the hydraulic system to operate at lower peak pressures by compensating with increased mechanical leverage when needed, thereby reducing the peak hydraulic power demand while still handling maximum loads.
Solution Approach 2:
The actuator system is segmented into variable geometric components that can be independently adjusted. This segmentation allows different parts of the actuation cycle to use different mechanical advantages, optimizing hydraulic pressure requirements for each phase of operation and reducing overall peak power demands.
3Reliability
If a larger hydraulic system is designed to meet peak power demands, then all actuators can be adequately powered, but the effective range and payload capacity of the aircraft are reduced
Solution Approach 1:
The variable moment arm actuator provides dynamic mechanical advantage adjustment, allowing a smaller, lighter hydraulic system to deliver the same peak torque as a larger system would provide at constant geometry. This reduces the size and weight of the hydraulic system while maintaining full capability to handle peak loads, thereby preserving payload capacity.
Solution Approach 2:
By changing the moment arm parameter dynamically, the system allows a reduced-size hydraulic system to achieve the same effective power output. The variable geometry compensates for the reduced hydraulic system size, ensuring that peak power demands are met without requiring an oversized hydraulic system that would increase aircraft weight and reduce payload capacity.
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
This solution reduces peak power demands and pressure loss, enhancing the aircraft's performance and payload capacity by enabling efficient actuation of flight control surfaces under varying load conditions.
Implementation Method 1
Each of the torque-generating hydraulic actuator and the VHR hydraulic actuator additionally includes a respective hydraulic valve that regulates a flow of hydraulic fluid relative to the respective hydraulic actuator housing to control a position of the respective rod relative to the respective hydraulic actuator housing
Implementation Method 2
The torque-generating hydraulic actuator is configured to apply a torque to the flight control surface to pivot the flight control surface relative to the support structure
Implementation Method 3
The VHR hydraulic actuator is configured to selectively vary an actuator moment arm length, as measured between the control surface pivot axis and the actuator coupling axis, to at least partially regulate the torque applied to the flight control surface by the torque-generating hydraulic actuator
Data Source
Figure 1
Figure 2
Figure 3
AI summary
Control surface actuator assemblies, aircraft hydraulic systems including the same, and associated aircraft and methods. A control surface actuator assembly includes a flight control surface (20) operatively coupled to a support structure (40), a torque-generating hydraulic actuator (2110) configured to apply a torque to pivot the flight control surface, and a variable horn radius (VHR) hydraulic actuator (1110) configured to vary an actuator moment arm length (30) for pivoting the flight control surface. In some examples, an aircraft hydraulic system includes such control surface actuator assemblies, and an aircraft includes such aircraft hydraulic systems. In some examples, a method of operating one or more flight control surfaces of an aircraft includes controlling a selected flight control surface by adjusting, with a VHR hydraulic actuator, an actuator moment arm length corresponding to the selected flight control surface and pivoting, with a torque-generating hydraulic actuator, the selected flight control surface.