Bearingless Rotor Head Using Flexible Composite Materials
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Solution Overview
Problem
Existing rotor designs for vertical takeoff and landing (VTOL) aircraft are complex, costly, and require additional dampers to manage vibratory movements, leading to increased aerodynamic drag and maintenance challenges.
Innovation Solution
A bearingless rotor head made from fiber-reinforced flexible matrix composite materials with integrated virtual hinges and damping capabilities, eliminating the need for discrete mechanical bearings and dampers, and featuring a monolithic structure for reduced complexity and cost.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If traditional mechanical bearings and hinges are used in rotor assemblies, then rotor blades can achieve necessary vibratory movement and twisting, but device complexity and cost significantly increase
Solution Approach 1:
The patent replaces traditional mechanical bearings and hinges with a bearingless rotor assembly that uses aerodynamic forces and flexible composite materials to enable vibratory movement. The rotor blades are constructed from flexible matrix composite materials that inherently provide the necessary flexibility and damping without requiring separate mechanical components, thereby reducing device complexity while maintaining operational capability.
Solution Approach 2:
The patent employs flexible matrix composite materials for the rotor blades, which combine structural integrity with inherent flexibility and vibration damping properties. These composite materials eliminate the need for separate mechanical bearings and dampers, as the material itself provides the necessary movement and vibration absorption characteristics, thus reducing overall device complexity.
2Reliability
If mechanical bearings and dampers are included in the rotor assembly, then vibratory movement is managed, but aerodynamic drag and cost increase
Solution Approach 1:
The patent eliminates mechanical bearings and dampers by using aerodynamic forces and flexible composite materials to manage vibratory movement. The bearingless design reduces aerodynamic drag by removing protruding mechanical components that would otherwise interfere with airflow, while the flexible composite materials provide inherent vibration damping without requiring additional drag-inducing dampers.
Solution Approach 2:
The rotor blades are designed to self-damp vibrations through their flexible composite material construction, eliminating the need for separate active or passive dampers. The material's inherent properties provide the necessary vibration management, reducing both cost and aerodynamic drag without compromising reliability.
3Ease of operation
If multiple hinges and bearings are used for rotor blade attachment, then flap and lead-lag movement is enabled, but maintenance time and costs increase
Solution Approach 1:
The patent replaces multiple mechanical hinges and bearings with a bearingless rotor assembly using flexible composite materials. This integration reduces the number of moving parts and potential failure points, making the system easier to maintain and repair. The flexible materials provide the necessary flap and lead-lag movement without requiring separate mechanical hinges, thereby simplifying maintenance procedures.
Solution Approach 2:
The use of flexible matrix composite materials integrates multiple functions (structural support, vibration damping, and movement enablement) into a single material system. This reduces the number of discrete components that require maintenance, as the composite structure inherently provides all necessary movement capabilities without separate mechanical hinges or bearings.
4Reliability
If independent active or passive dampers are added to bearingless rotor assemblies, then vibration damping is improved, but device complexity and cost remain high
Solution Approach 1:
The rotor blades are designed with inherent vibration damping capabilities through their flexible composite material construction. The materials themselves provide the necessary damping without requiring separate active or passive dampers, allowing the system to self-regulate vibrations. This eliminates additional components and reduces device complexity while maintaining effective vibration control.
Solution Approach 2:
The flexible matrix composite materials used in the rotor blades inherently provide vibration damping properties, eliminating the need for separate dampers. The composite structure's material properties are engineered to absorb and dissipate vibrations, providing reliable vibration control while reducing overall device complexity and cost.
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
The solution effectively manages flap, lead-lag, and torsional loads through material strain and deformation, reducing vibrations and stresses, and providing intrinsic passive damping without active dampers, thus simplifying the rotor design and reducing maintenance costs.
Implementation Method 1
The rotor head may be configured from or otherwise include fiber reinforced flexible matrix composite materials
Implementation Method 2
One or more of the attachment structures may each be configured from or otherwise include material operable to damp flap, lead-lag and/or torsional rotor blade movement
Data Source
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AI summary
An apparatus is provided for a vertical take-off and landing aircraft. The apparatus includes a rotor head (40) with a rotor hub (52) and a plurality of rotor blade attachment structures (54). The attachment structures (54) are disposed about and extend radially out from the rotor hub (52). Each of the attachment structures (54) may be configured from or otherwise include flexible matrix composite material. In addition or alternatively, the rotor head (40) may be a monolithic bearingless rotor head.