Integrated Rotor Hub and Shaft for Rotary Wing Aircraft
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Solution Overview
Problem
Conventional rotor hub assemblies for rotary wing aircraft are heavy due to multiple components and large shaft nuts, and they require significant openings for counter-rotating systems, which increases weight and complexity.
Innovation Solution
A main rotor system with a hollow rotor shaft and an upper rotor hub integrally formed with equidistantly spaced rotor members, allowing for a reduced wall thickness and open center for access, which reduces weight and size while maintaining structural integrity and access to internal components.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If conventional rotor hub assemblies with multiple components and large shaft nuts are used, then structural integrity and retention are ensured, but the empty weight of the helicopter increases
Solution Approach 1:
The rotor hub and rotor shaft are integrated into a single unified structure, eliminating the need for separate hub components, shaft nuts, and locking mechanisms. This merging reduces the number of parts and overall weight while maintaining structural integrity through the continuous load path from blade roots through the hub and into the shaft.
Solution Approach 2:
The integrated hub-shaft structure serves multiple functions simultaneously: it provides structural support, transmits torque, maintains blade positioning, and eliminates the need for separate retention mechanisms. This multi-functionality reduces the total component count and weight while ensuring all necessary functions are fulfilled.
2Ease of repair
If a large opening is machined into the hub for access to upper rotor shaft components, then maintenance access is improved, but the structural strength and weight are reduced
Solution Approach 1:
The integrated hub-shaft structure is designed with segmented access features that allow maintenance personnel to access upper rotor shaft components without requiring a large opening. The segmentation allows for targeted access points that minimize structural disruption while providing adequate maintenance capability.
Solution Approach 2:
The design extracts the access function from the hub structure itself, allowing maintenance access to upper rotor shaft components through the integrated structure without compromising the hub's structural integrity. This is achieved by designing the integration to include built-in access pathways or removable sections.
3Ease of manufacture
If multiple separate components are used in the rotor hub assembly, then ease of manufacturing individual parts is improved, but the overall device complexity and weight increase
Solution Approach 1:
The rotor hub and rotor shaft are manufactured as a single integrated component, eliminating the need for assembly of multiple separate parts. This reduces assembly complexity, minimizes the number of fasteners and connections required, and reduces overall weight while maintaining manufacturability through modern manufacturing processes.
Data Source
AI summary
A main rotor system for a rotary wing aircraft is provided including a lower rotor hub to which lower rotor blades are attachable. The lower rotor hub rotates about an axis in a first direction. A hollow rotor shaft extends through the lower rotor hub. The first end of the rotor shaft couples to a component of the rotary wing aircraft for rotation about an axis. An upper rotor hub arranged at the second end of the rotor shaft includes a plurality of similar upper rotor members equidistantly spaced about a circumference of the rotor shaft to form an open center aligned with a hollow interior of the rotor shaft. An opening configured to receive an upper rotor blade is formed between adjacent upper rotor members and the upper rotor hub is configured to rotate in a second direction, opposite the first direction.