Unducted Propeller Blade Pitch Assembly with Flexible Debris Retention
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Solution Overview
Problem
Aircraft turbomachine propellers with variable-pitch blades face challenges in aerodynamic efficiency due to aerodynamic discontinuities at the hub, and the risk of debris striking the fuselage during blade failure is high due to metal parts with high density.
Innovation Solution
An assembly for an unducted propeller blade with a claw-like support member that is elastically deformable to absorb axial displacement of the blade root, featuring a claw that flexes to absorb kinetic energy and prevent debris from striking the fuselage, and a platform that enhances aerodynamic continuity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If metal parts with high density are used in the blade root assembly, then mechanical strength and reliability are improved, but the risk of fuselage damage from debris increases
Solution Approach 1:
The invention extracts and removes the heavy metal parts (barrel and bearing) from the blade root assembly, retaining only the essential bearing function while eliminating the harmful high-density metal components that create dangerous debris in case of blade failure
Solution Approach 2:
The invention converts the potential harm of metal debris into a benefit by using a lightweight support member that, if it fails, produces harmless lightweight debris instead of dangerous high-density metal fragments, while still providing the necessary mechanical support function
2Reliability
If traditional blade root assembly with metal barrel and bearing is used, then reliability is improved, but aerodynamic efficiency deteriorates due to turbulence
Solution Approach 1:
The invention removes the metal barrel component that creates aerodynamic discontinuities and turbulence, keeping only the essential bearing function integrated into a streamlined support member that maintains reliability while improving aerodynamic efficiency
Solution Approach 2:
The invention uses a lightweight support member with a streamlined, aerodynamic shape that reduces turbulence and improves flow characteristics around the blade root, while still providing the necessary structural support and bearing functions
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
Improves aerodynamic efficiency by reducing turbulence and minimizes the risk of fuselage damage from debris by converting kinetic energy into deformation energy, thereby enhancing safety and performance.
Implementation Method 1
the claw being capable of flexing to absorb axial displacement of the blade root in the event of failure of the root immobilizing member in the bowl
Implementation Method 2
converting kinetic energy into deformation energy
Data Source
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AI summary
The invention relates to an assembly for an aircraft turbine engine, including an unducted propeller blade (10) and a system (34) for setting the pitch of the blade (10) and further comprising: - a blade (10) of which the root (14) has a bulbous portion (32); - a system (34) for setting the pitch of the blade (10) about a pitch setting axis (A), the pitch setting system (34) comprising a cup (58), which is intended to be placed inside the outer casing (73), has a flared open top end for axial insertion of the root (14) and in which the root (14) of the blade (10) is axially affixed by a locking member (52); the assembly being characterised in that it further comprises at least one radial retention prong (77) in a radial space (E) reserved between the wall (58a) of the cup (58) and the root (14).