Additive Manufactured Proprotor Blade with Hex-Core Skin
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Solution Overview
Problem
Conventional rotor blade assemblies with internal torque tubes, or D-spar, are structurally complex and costly to manufacture due to tight internal radii and complicated material transitions, making them difficult and time-consuming to produce.
Innovation Solution
The rotor blade assembly eliminates the internal tubular spar by using a structural skin extending spanwise and chordwise, with a hex-shaped structural core oriented normal to the skin, fabricated through additive 3D printing, which is bonded to the skin using an inner mold line tooling process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If an internal torque tube (D-spar) is used to provide structural strength and stiffness, then the blade assembly achieves required mechanical properties, but the manufacturing complexity and cost increase significantly
Solution Approach 1:
The patent removes the internal torque tube (D-spar) from the blade assembly design. Instead of using a separate internal structural component, the design relies on the structural skin itself to provide the necessary strength and stiffness, thereby eliminating the manufacturing complexities associated with tight internal radii and complicated material transitions of the D-spar
Solution Approach 2:
The patent merges the functions of the skin and the internal spar into a single integrated structural skin component. The structural skin is designed to perform both the traditional skin function and the structural support function previously provided by the separate D-spar, simplifying the overall structure and manufacturing process
2Strength
If an internal torque tube (D-spar) is used to provide structural strength, then the blade assembly achieves required mechanical properties, but the manufacturing time and cost increase
Solution Approach 1:
By removing the internal torque tube from the design, the patent eliminates the time-consuming manufacturing steps associated with creating tight internal radii and executing complicated material transitions, significantly reducing overall manufacturing time while maintaining structural strength through the integrated structural skin
3Strength
If an internal torque tube (D-spar) is used to provide structural strength, then the blade assembly achieves required mechanical properties, but the manufacturing cost increases
Solution Approach 1:
The patent eliminates the internal torque tube, removing the need for expensive manufacturing processes required to create complex internal geometries with tight radii and multiple material transitions, thereby reducing manufacturing cost while maintaining structural integrity
Solution Approach 2:
By integrating the structural support function into the skin, the patent reduces the total number of components and manufacturing steps, leading to lower material costs, reduced labor requirements, and overall lower manufacturing cost while maintaining the necessary structural strength
Data Source
AI summary
An exemplary proprotor blade assembly includes a structural skin extending spanwise from a root to a tip and along a chord from leading edge to a trailing edge and a structural core positioned inside of the structural skin, the structural skin comprising hex-shaped structures oriented normal to the structural skin.