Rotor Blade Pitch-Fold Locking for Stiff Lightweight Tiltrotors
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Solution Overview
Problem
Tiltrotor aircraft face limitations in forward airspeed and range due to rotor system constraints, and existing blade locking mechanisms lack sufficient stiffness and require additional components for secure locking.
Innovation Solution
The introduction of dual-output shaft actuators and passive overcenter locking mechanisms in the pitch-fold lock systems, which provide improved stiffness and secure locking without additional components, allowing for easier installation and reduced weight.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If traditional blade locking mechanisms are used, then the structure is simpler, but the stiffness is insufficient and additional components are required
Solution Approach 1:
The patent combines the pitch lock and fold lock functions into a single integrated locking mechanism. The dual-output shaft actuator simultaneously controls both pitch and fold locking, eliminating the need for separate locking systems and reducing overall structural complexity while maintaining sufficient stiffness through the unified design.
Solution Approach 2:
The locking mechanism is designed to perform multiple functions: it provides both pitch locking and fold locking capabilities through a single system. The dual-output shaft actuator can independently control pitch blade angles and fold blade angles, making the mechanism universal and eliminating the need for additional dedicated components for each function.
2Reliability
If additional components are added to improve locking security, then the locking reliability increases, but the weight increases
Solution Approach 1:
By merging pitch locking and fold locking into a single integrated mechanism, the patent achieves reliable locking for both functions without the weight penalty of separate locking systems. The dual-output shaft actuator provides redundant control capability while maintaining a compact, lightweight structure.
Solution Approach 2:
The universal locking mechanism performs multiple locking functions through a single system, providing high reliability without requiring additional dedicated components for each function. This multi-functionality eliminates the need for separate pitch locks and fold locks, reducing overall weight while maintaining security.
3Reliability
If more components are used for secure locking, then the locking security improves, but the installation complexity increases
Solution Approach 1:
The integration of pitch and fold locking into a single mechanism significantly simplifies installation procedures. Instead of installing and aligning multiple separate locking systems, the dual-output shaft actuator provides a unified installation process while maintaining secure locking through its combined design.
4Speed
If traditional rotor systems are used in tiltrotor aircraft, then the vertical lift capability is maintained, but the forward airspeed and range are limited
Solution Approach 1:
The patent implements a dynamic blade locking system that can transition between different locking states during flight operations. The dual-output shaft actuator enables real-time adjustment of pitch and fold blade angles, allowing the rotor system to adapt between vertical lift configuration and forward flight configuration, thereby achieving both high forward airspeed and maintained versatility.
Data Source
AI summary
A rotor-blade assembly has a lock system to enable and disable a folding degree of freedom and a pitching degree of freedom of a rotor blade. A grip couples a blade to a hub, the blade being pivotable about a fold axis relative to the grip, the blade and grip being pivotable together about a pitch axis relative to the hub. A fold lock prevents folding of the blade in a fold-lock position and allows folding of the rotor blade in a pitch-lock position, and a pitch lock allows pitch movement of the rotor blade in a fold-lock position and prevents pitch movement of the rotor blade in the pitch-lock position. A rotary actuator carried by the grip has actuator arms coupled through linkage to the pitch lock and fold lock, and the actuator is configured for moving the pitch lock and fold lock between the fold-lock and pitch-lock positions.