Dynamic Rotor-Phasing Unit for Tiltrotor Storage and Tuning
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Solution Overview
Problem
Rotorcraft with adjustable-phase rotors face challenges in minimizing storage area requirements due to radial extension of rotor blades, and existing phasing methods often require disconnection of the drive system, leading to potential failures and accuracy issues.
Innovation Solution
A dynamic rotor-phasing unit that allows for in-flight phasing of rotors by clocking input and output shafts from 0 to over 360 degrees, using a planetary or slider configuration with actuators and gears to maintain continuous drive system connectivity, enabling rotor blades to be folded within a smaller area without disconnection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If rotor blades radially extend past the fuselage to generate sufficient lift, then lift generation is improved, but the footprint and storage area requirements increase
Solution Approach 1:
The rotor blades are configured to be dynamically adjustable between an extended operational position for lift generation and a retracted storage position. The tilting mechanism allows the rotor assembly to transition from a horizontal configuration during flight to a vertical configuration for storage, minimizing the footprint without compromising lift capability when needed
2Area of stationary object
If the rotor blades are removed from the rotorcraft to minimize storage area, then storage area requirements are reduced, but the process is time consuming and results in lost or damaged components
Solution Approach 1:
Instead of removing rotor blades, the system uses a dynamic tilting mechanism that allows the rotor assembly to be rotated into a vertical storage position while remaining connected to the drive system. This eliminates the time-consuming removal process and prevents component loss or damage while achieving compact storage
3Area of stationary object
If the rotors are disconnected from the drive system and manually rotated to minimize storage area, then storage area is reduced, but personnel must manually rotate the rotor blades
Solution Approach 1:
The system employs an automated tilting mechanism with actuators that rotate the rotor assembly from horizontal to vertical position without manual intervention. The mechanism maintains drive system connection throughout the transition, eliminating the need for disconnection and manual rotation while achieving compact storage configuration
4Adaptability or versatility
If a clutch is used to phase the rotor assemblies relative to each other during flight, then real-time rotor phasing is achieved, but repeated connection and disconnection introduces unnecessary failures
Solution Approach 1:
The patent uses continuously variable phasing mechanisms that allow rotor assemblies to be phased relative to each other while maintaining constant drive system connection. The tilting and phasing operations are performed through integrated mechanical linkages that eliminate the need for repeated clutch engagement and disengagement, thereby maintaining adaptability while significantly improving reliability
5Adaptability or versatility
If a clutch is used to disconnect and reconnect output shafts for rotor phasing, then rotor blade offset is achieved, but maintaining repeatable accuracy in the amount of phasing becomes challenging
Solution Approach 1:
The system employs precision mechanical linkages and gear mechanisms that provide controlled, repeatable rotor phasing through continuous rotation. The integrated tilting and phasing mechanism uses fixed geometric relationships and precision-machined components to achieve accurate, repeatable phasing angles without the cumulative errors that result from repeated clutch engagement and disengagement
Data Source
AI summary
A dynamic rotor-phasing unit can phase rotors in-flight for dynamic rotor tuning and in an idle state for aircraft storage. The input and output shafts can be clocked (e.g., rotated) from 0 degrees apart to in excess of 360 degrees apart or from 0 degrees apart to 140 degrees apart. Such rotation can minimize the footprint of an aircraft for stowing purposes, as the rotor blades can be folded to fit within a smaller area without disconnecting the drive system. Additionally, the unit can allow tiltrotor blades to be clocked during flight, which can allow the live-tuning of the aircraft's rotor dynamics. A fail-safe rotary actuator can rotate a stationary planet carrier to clock the input shaft and the output shaft. Alternatively, an actuator can position a slider housing to clock the input shaft and the output shaft.