Aircraft Wing Tip Hinge With Geared Rotary Actuator for Low Drag
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Solution Overview
Problem
Folding wing tip devices on aircraft create additional drag due to large fairings required to cover protruding hinge arrangements, which affect aerodynamic performance and fuel efficiency.
Innovation Solution
Aircraft wing design incorporating a hinge arrangement with a geared rotary actuator (GRA) partially located within interface rings, allowing for a reduced fairing size or eliminating the need for a fairing altogether, by aligning the hinge axis with the flight direction and using splined or toothed surfaces for efficient rotational coupling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a traditional hinge arrangement with interleaved lugs is used to connect the fixed wing and wing tip device, then the wing tip device can be moved between flight and ground configurations, but the hinge arrangement protrudes beyond the wing skin requiring large fairings that increase drag and reduce fuel efficiency
Solution Approach 1:
The geared rotary actuator is partially located within the fixed wing interface ring and wing tip device interface ring, with components nested inside each other. The GRA drive mechanism is housed within the interface rings themselves, eliminating the need for external protruding structures and large fairings, thereby reducing drag and improving fuel efficiency while maintaining configurability
2Ease of operation
If the hinge arrangement protrudes significantly beyond the wing skin to avoid fouling the fairing during movement, then the wing tip device can move between configurations, but the fairing size increases creating additional drag
Solution Approach 1:
The hinge arrangement components are nested within the interface rings rather than protruding externally. The GRA actuator is housed inside the interface ring structure, allowing the wing tip device to move between configurations without requiring large external fairings, thus reducing drag while maintaining operational ease
Solution Approach 2:
The hinge axis is aligned with the line of flight direction or angled up to 15 degrees relative to it, changing the orientation dimension of the hinge arrangement. This dimensional reorientation allows the mechanism to operate with minimal protrusion, reducing the fairing size required and thereby reducing drag
3Reliability
If a large fairing is used to cover the protruding hinge arrangement, then the hinge components are protected from airflow interference, but the aerodynamic performance is adversely affected due to increased drag
Solution Approach 1:
The hinge arrangement components are nested within the interface rings, with the GRA actuator housed inside the ring structure. This nested configuration protects the hinge components from airflow interference without requiring large external fairings, thereby maintaining reliability while minimizing drag and preserving aerodynamic performance
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
Reduces drag and maintains aerodynamic performance by minimizing the fairing size, enhancing fuel efficiency and facilitating easier maintenance of the wing components.
Implementation Method 1
a geared rotary actuator (GRA) partially located within the fixed wing interface ring and wing tip device interface ring, and arranged to drive the wing tip device interface ring to move the wing tip device between the flight configuration and ground configuration
Data Source
Figure 1a
Figure 1b
Figure 2a
AI summary
The invention provides an aircraft wing (100) with a wing tip device (14) movable between a flight configuration for use during flight and a ground configuration for use during ground-based operations. In the ground configuration the wing tip device (14) is moved away from the flight configuration such that the span of the aircraft wing is reduced. A hinge arrangement (16) connects the fixed wing and the wing tip device. The hinge arrangement comprises a plurality of fixed wing interface rings (40), a plurality of wing tip device interface rings (41), and a geared rotary actuator (38, GRA) partially located within the fixed wing interface rings and wing tip device interface rings. The GRA is arranged to drive the wing tip device interface rings to move the wing tip device between the flight configuration and ground configuration.