Aircraft Spoiler Actuation System with Rack and Pinion
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Aircraft spoiler actuation systems occupy significant space within the wing, limiting the size of the spar box and reducing fuel capacity, and existing systems suffer from inaccurate position control and hydraulic leakage issues that increase drag during flight.
Innovation Solution
A spoiler actuation system that reduces space requirements by using a servo-valve controlled hydraulic system with a rack and pinion mechanism, coupled with a rotary position sensor for accurate control and a mechanical locking mechanism to prevent upward travel during hydraulic failures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of stationary object
If traditional spoiler actuation systems are used, then spoiler control function is achieved, but significant space within the wing is occupied, limiting spar box size and fuel capacity
Solution Approach 1:
The patent replaces traditional complex mechanical actuation linkages with a simplified rack and pinion mechanism driven by a single actuator. This substitution reduces the number of mechanical components and the space they occupy within the wing, thereby increasing the available volume for the spar box and fuel storage.
Solution Approach 2:
The actuation system is designed to perform multiple functions within a compact space: it provides spoiler deployment, positioning, and mechanical locking capabilities using integrated components. The rack and pinion mechanism serves both as the primary actuation mechanism and as part of the positioning system, eliminating the need for separate mechanisms and reducing overall space requirements.
2Measurement precision
If hydraulic systems are used for spoiler actuation, then positioning capability is achieved, but hydraulic leakage occurs causing spoiler float and increased drag
Solution Approach 1:
The system incorporates a mechanical locking mechanism that engages at the desired spoiler position, preventing any potential drift or float caused by hydraulic leakage. This preliminary mechanical constraint acts as a backup to counteract the harmful effects of hydraulic system imperfections, ensuring the spoiler remains firmly positioned without generating drag from float.
Solution Approach 2:
The mechanical locking mechanism serves as an intermediary between the hydraulic actuation system and the spoiler. It translates the hydraulic positioning action into a mechanically locked state, providing a reliable position hold that is independent of hydraulic leakage. This intermediary mechanism ensures accurate positioning while eliminating the drag-causing float effect.
3Reliability
If mechanical locking mechanism is added to prevent upward travel, then reliability during hydraulic failure is improved, but device complexity increases
Solution Approach 1:
The mechanical locking mechanism is merged with the existing rack and pinion actuation mechanism rather than being added as a completely separate system. The locking components are integrated into the same structural framework and share common mounting points and control logic, thereby providing enhanced reliability during hydraulic failure while minimizing the increase in overall device complexity.
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 increased fuel storage capacity by minimizing space usage within the wing while ensuring accurate spoiler positioning and reducing drag by preventing hydraulic leakage-induced float, thus enhancing aircraft performance range.
Implementation Method 1
a servo-valve to switch between a neutral state, a third state and a fourth state in response to the control signal, the servo-valve to prevent flow of hydraulic fluid therethrough in the neutral state, the servo-valve to direct the hydraulic fluid from the hydraulic system toward the first piston in the fourth state, and the servo-valve to direct the hydraulic fluid toward the second piston in the third state
Implementation Method 2
A rack is movable between a first position and a second position. A pinion is coupled to the rack, the pinion to rotate between a third position and a fourth position when the rack moves between the first position and the second position
Data Source
Figure 1
Figure 2A~2B
Figure 3A~3B
AI summary
An example aircraft disclosed herein includes a wing, a spoiler rotatably coupled to the wing, the spoiler movable between a cruise position and an upward position and between the cruise position and a droop position, and a spoiler actuation system coupled to a hydraulic system of the aircraft, the spoiler actuation system including a first piston and a second piston, a rack coupled between the first piston and the second piston, the rack movable between a first position and a second position, a pinion coupled to the rack, the pinion to rotate between a third position and a fourth position when the rack moves between the first position and the second position, a first crank arm coupled to the pinion, the first crank arm to rotate with the pinion between the third position and the fourth position, and a second crank arm coupled to the first crank arm and to the spoiler, the second crank arm to move the spoiler between the cruise position and the upward position when the first crank arm rotates between the third position and the fourth position.