Stacked Swashplate Assemblies for Individual Rotorcraft Blade Control
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Solution Overview
Problem
Current blade control systems for rotorcraft are limited by size and power, preventing effective individual blade control to reduce wake turbulence and instability during edgewise flight, which results in increased power consumption and noise.
Innovation Solution
A blade pitch control system featuring serially stacked swashplate assemblies with concentric, ring-shaped sections and actuators, allowing independent control of each blade's pitch through sliding mechanisms and guide rollers, enabling precise control of blade pitch and reducing turbulence.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If individual blade control is implemented to reduce wake turbulence and instability, then rotorcraft performance and stability are improved, but the size and power requirements of the control system increase beyond practical limits
Solution Approach 1:
The control system is segmented into multiple independent swashplate assemblies, with each assembly dedicated to controlling a specific blade. This segmentation allows each unit to be compact and manageable in size while collectively providing individual control for all blades, resolving the contradiction between comprehensive blade control and system size complexity
Solution Approach 2:
The swashplate assemblies are nested or stacked one on top of another in a compact arrangement around the rotor mast. This nesting principle allows multiple control units to occupy minimal space while maintaining their individual functionality, enabling individual blade control without excessive system size
2Object-generated harmful factors
If high frequency blade oscillation is implemented to match vortex shedding periodicity, then wake turbulence is reduced, but the power required to drive the oscillation increases
Solution Approach 1:
The system implements periodic oscillation of each blade at frequencies that match the vortex shedding periodicity. By synchronizing the blade oscillation with the natural vortex shedding frequency, the system reduces wake turbulence through constructive interference patterns while minimizing the additional power required, as the oscillation exploits rather than fights the natural aerodynamic phenomena
Solution Approach 2:
The system changes the operational parameters of blade pitch oscillation, specifically the frequency and amplitude, to optimize the balance between turbulence reduction and power consumption. By adjusting these parameters to match the vortex shedding characteristics, the system achieves effective turbulence control with minimal power input
Data Source
AI summary
A blade pitch control system includes a plurality of serially stacked swashplate assemblies, each having concentric, ring-shaped inner and outer sections, an associated output pitch link coupled to its outer section and an associated input pitch link coupled to its inner section. The inner and outer sections of each swashplate assembly includes pass through holes to accommodate input pitch links and output pitch links of adjacent ones of the stacked swashplate assemblies. The system also includes a plurality of actuators, each coupled to a respective input pitch link of a respective one of the stacked swashplate assemblies. A central static mast accommodates a rotor drive shaft and the stacked swashplate assemblies are configured to slide axially, parallel to a long axis of the static mast.