Rotor Hub Assembly With Cyclic Pitch Control for Vibration Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing rotor assemblies in air mobility vehicles (AMVs) face issues with vibrations and noise due to the use of two-bladed fixed pitch rotors lacking cyclic pitch control, leading to a less pleasurable ride for passengers.
Innovation Solution
A rotor assembly design that includes a hub assembly coupled to a shaft assembly via a gimbal and linkages, allowing for cyclic pitch control without the need for a swashplate, reducing vibrations and noise through a simple actuator configuration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If two-bladed fixed pitch rotors are used without cyclic pitch control, then device complexity is reduced, but vibrations and noise increase
Solution Approach 1:
The rotor assembly is segmented into distinct functional components: a hub assembly with pitch control mechanism, a shaft assembly, and rotor blades. The hub assembly contains a pitch linkage system with arms and linkages that can independently adjust blade pitch, separating the pitch control function from the rotation function. This segmentation allows cyclic pitch control to be implemented without requiring a complex swashplate mechanism, thereby reducing overall device complexity while still mitigating vibrations and noise through active pitch adjustment.
2Device complexity
If cyclic pitch control is implemented without swashplate, then device complexity is reduced, but manufacturing precision requirements increase
Solution Approach 1:
The pitch linkage system acts as an intermediary mechanism between the actuator and the rotor blades. The linkage includes arms connected to the hub and linkages that transmit motion from actuators to the blades, providing a mechanical advantage system that amplifies small actuator movements into precise blade pitch changes. This intermediary mechanism achieves the required manufacturing precision through mechanical leverage and geometric relationships rather than requiring extremely tight tolerances on all components, thus reducing overall device complexity while maintaining pitch control precision.
3Weight of moving object
If two-bladed rotors are used, then weight is reduced, but vibrations increase during edgewise flight
Solution Approach 1:
The rotor system employs dynamic pitch adjustment through the pitch control mechanism in the hub assembly. During edgewise flight, the actuators actively modify the pitch angle of the blades in real-time to compensate for the lift disparity between advancing and retreating blades. This dynamic adjustment allows the lightweight two-bladed rotor to maintain balanced aerodynamic forces throughout the rotation, effectively mitigating vibrations without adding the weight penalty of a swashplate mechanism, thus resolving the contradiction between weight reduction and vibration control.
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 design effectively reduces vibrations and noise during takeoff and edgewise flight operations, providing a smoother ride for passengers by enabling cyclic pitch control in a lightweight and less complex rotor assembly.
Implementation Method 1
the second coupling may be configured to facilitate rotation of the hub relative to a shaft of the shaft assembly
Implementation Method 2
the first coupling may be configured to transmit movements of the actuator to the hub to facilitate cyclic pitch control of the rotor blade
Data Source
AI summary
A rotor assembly includes a hub assembly and a shaft assembly. The hub assembly includes a hub and a first coupling, and the shaft assembly may be coupled to the hub assembly with a second coupling. The second coupling may be configured to facilitate rotation of the hub relative to a shaft of the shaft assembly. A rotor blade may be coupled to the hub assembly with a third coupling and be configured to rotate with the shaft. The first coupling may be configured to couple the hub to an actuator and transmit movements of the actuator to the hub to facilitate cyclic pitch control of the rotor blade. The rotor shaft may include arms and the hub may include a body coupled to the rotor blade by the third coupling and pairs of extensions that extend from a surface of the body to receive the arms.