Centrifugal Fold-Out Propeller Tips for Variable UAV Disk Area

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Solution Overview

Problem

Existing unmanned aerial vehicles (UAVs) face limitations in propeller disk area due to physical constraints, leading to potential conflicts with the environment and increased drag during different operational states, such as takeoff, landing, and forward flight.

Innovation Solution

Propeller blades with movable distal ends that expand under centrifugal force to increase disk area during forward flight, allowing for larger disk area without interference and reduced drag.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Area of moving object

If the propeller diameter is increased to improve propeller efficiency and disk area, then the propeller may conflict with the landing environment and increase drag during certain operations

Engineering Contradiction:
Improvepropeller disk areaVSAvoidconflicts with landing environment and drag
Core Design Contradiction:
Area of moving objectVSObject-affected harmful factors

Solution Approach 1:

The propeller blade incorporates a movable distal end portion that can dynamically change position between extended and retracted states. This dynamic structure allows the propeller to adapt its disk area based on operational requirements, resolving the contradiction between needing large disk area for efficiency and avoiding conflicts/drag during specific operations.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The invention changes the physical parameter of propeller blade length by making the distal end portion movable. This parameter change allows the effective propeller diameter and disk area to vary between operational states, enabling optimization of propeller efficiency when needed while minimizing conflicts and drag when the propeller is retracted.

Inventive Principle:
Principle #35Parameter changes

2Device complexity

If the propeller blade is made fixed to maintain structural simplicity, then the disk area cannot be increased without causing environmental conflicts and increased drag

Engineering Contradiction:
Improvepropeller structureVSAvoidpropeller disk area
Core Design Contradiction:
Device complexityVSArea of moving object

Solution Approach 1:

Rather than making the entire propeller structure complex and movable, the invention selectively makes only the distal end portion of the blade movable while keeping the proximal portion fixed. This dynamic approach increases disk area capability without proportionally increasing overall structural complexity.

Inventive Principle:
Principle #15Dynamics

3Productivity

If the propeller distal end is made movable to reduce drag and conflicts, then the propeller efficiency can be optimized across different operational states

Engineering Contradiction:
Improvepropeller efficiencyVSAvoidpropeller blade structure
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The invention applies different structural qualities to different parts of the propeller blade. The proximal portion maintains a fixed, simple structure for structural stability, while the distal end portion is made movable to optimize efficiency and reduce drag. This local differentiation allows efficiency optimization without uniformly increasing complexity across the entire blade.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The movable distal end portion enables the propeller to dynamically adjust its configuration based on operational states, improving productivity by reducing drag during operations where smaller effective area is beneficial while maintaining the capability for larger disk area when efficiency is prioritized.

Inventive Principle:
Principle #15Dynamics

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

Enhances propeller efficiency by increasing disk area during forward flight while minimizing conflicts and drag, optimizing performance across various operational states.

Implementation Method 1

A centrifugal force acting on the thrust propeller blade causes a thrust propeller disk area to increase from a first disk area when the UAV is in a first operational state to a second disk area when the UAV is in a second operational state

Methodology Applied
Scientific EffectCentrifugal force: Centrifugal Force

Data Source

PatentEP4149837B1Fold-out propeller tip extensions
Publication Date: 2025.10.29 WING AVIATION LLC
  • EP4149837B1 patent drawingFigure 1A
  • EP4149837B1 patent drawingFigure 1B~1C
  • EP4149837B1 patent drawingFigure 1D

AI summary

A propeller blade for an unmanned aerial vehicle ("UAV") is disclosed. The UAV includes a plurality of lift propellers and at least one thrust propeller. Each of the plurality of thrust propellers includes a thrust propeller blade coupled to a hub of the thrust propeller. The thrust propeller blade is configured such that a centrifugal force acting on the thrust propeller blade causes a thrust propeller disk area to increase from a first disk area when the UAV is in a first operational state to a second disk area when the UAV is in a second operational state.