Rotor Assemblies With Elastomeric Hub Connectors
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Traditional rotor assemblies for rotorcraft, such as helicopters, are complex and require periodic lubrication due to their thrust and pitch bearing joints, which increases maintenance and reduces efficiency.
Innovation Solution
A rotor assembly design featuring a rotor hub with N-fold rotational symmetry, where each rotor blade is supported by a flap axle, hub connector, and torsion strap, allowing for independent pivotability and reducing the need for a single torsion strap between opposing blades, thus simplifying the configuration and reducing packaging volume.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional rotor assemblies use thrust and pitch bearing joints, then the rotor can achieve controlled pitch and passive flap motion, but the assembly requires periodic lubrication which increases maintenance and reduces efficiency
Solution Approach 1:
The patent replaces traditional mechanical bearing joints with elastomeric elements that provide both structural support and bearing functions. The elastomeric hub connectors and blade root elements eliminate the need for separate thrust and pitch bearings, removing lubrication requirements while maintaining controlled pitch and passive flap capabilities through the elastomeric material's inherent properties
Solution Approach 2:
The invention changes the material parameter from rigid metal bearings to flexible elastomeric materials. This parameter change allows the same components to perform multiple functions (structural support, thrust bearing, pitch control, flap motion) without requiring periodic lubrication, thereby improving reliability while managing device complexity through material selection
2Device complexity
If a single torsion strap extends between two opposing rotor blades, then the structure is simplified, but the packaging envelope and complexity increase for rotor assemblies with greater than two blades
Solution Approach 1:
The patent segments the torsion strap system by providing an individual torsion strap for each rotor blade rather than using a single strap spanning multiple blades. This segmentation allows each blade to have its own independent torsion element, reducing the overall packaging envelope and simplifying the structural configuration for rotor assemblies with three or more blades while maintaining necessary flexibility and control
3Volume of stationary object
If each rotor blade has its own torsion strap, then the packaging volume and complexity are reduced, but the structural design becomes more intricate
Solution Approach 1:
The patent applies universality by designing the elastomeric hub connectors and blade root elements to perform multiple functions simultaneously. Each elastomeric component serves as both a structural connector and a torsion element, eliminating the need for separate torsion straps while reducing packaging volume. This multi-functionality approach simplifies the overall design rather than increasing it, as the same elastomeric elements provide both structural support and flexible torsion capabilities
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
This design reduces complexity and packaging volume, eliminates the need for periodic lubrication, and enhances the stability and efficiency of rotor assemblies by allowing each rotor blade to have its own torsion strap, improving the overall performance and maintenance of rotorcraft.
Implementation Method 1
The torsion strap has a first end, coupled to the rotor blade, and a second end, through which the flap axle passes
Implementation Method 2
Each of the rotor-blade assemblies is rotatable relative to the rotor hub about the rotation axis via a pair of bearing assemblies
Data Source
AI summary
A rotor assembly comprises a rotor hub and rotor-blade assemblies. The rotor hub comprises rotor-blade supports. Each rotor-blade assembly is coupled to a respective one of the rotor-blade supports and comprises a flap axle, a hub connector, a rotor blade, and a torsion strap. The flap axle extends through a respective one of the rotor-blade supports and has a central flap-axle axis. The hub connector is pivotable relative to a rotor-blade support about the central flap-axle axis and defines a central hub-connector axis. The rotor blade is coupled to and is pivotable relative to the hub connector, and, together with the hub connector, is pivotable relative to a respective one of the rotor-blade supports about the central flap-axle axis. The torsion strap has a first end, coupled to the rotor blade, and a second end, through which the flap axle passes.