Propeller Assembly with Pivoting Stacked Blades for Aircraft
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Solution Overview
Problem
Aircraft propellers face challenges in generating high vertical thrust at low rotational velocities while minimizing drag force during forward flight, as multi-bladed propellers produce undesirable drag when not generating vertical thrust.
Innovation Solution
A propeller assembly with a coupling shaft and stacked propellers that pivot relative to each other, featuring a coupling assembly transitioning between stowed and deployed configurations based on rotational velocity, optimizing blade offset angles to maximize thrust or minimize drag.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If the number of propellers and/or propeller blades is increased to maximize vertical thrust production at low rotational velocities, then vertical thrust is improved, but drag force increases when the propellers are not in use
Solution Approach 1:
The propeller assembly employs a dynamic configuration system where multiple propellers can pivot between a deployed position (for maximum vertical thrust during takeoff and landing) and a stowed position (for minimum drag during forward flight). The coupling assembly allows the propellers to change their spatial arrangement based on operational requirements, transforming the static propeller design into a dynamic one that adapts to different flight phases.
Solution Approach 2:
The invention introduces a new spatial dimension for propeller arrangement by allowing propellers to pivot about the rotation axis. This creates a degree of freedom in the radial plane, enabling the propellers to be positioned at different angular offsets from one another. This dimensional change allows the system to achieve both high thrust (when propellers are spread out) and low drag (when propellers are consolidated) by utilizing angular positioning.
2Productivity
If propellers are configured for maximum vertical thrust at low rotational velocities, then thrust efficiency is improved, but the propeller structure complexity increases
Solution Approach 1:
The propeller assembly is segmented into multiple independent propeller units, each capable of pivoting relative to the others. This segmentation allows each propeller blade to be optimized for thrust generation while the coupling assembly manages their relative positions. The segmentation enables independent optimization of each blade for thrust efficiency while the overall system manages complexity through modular architecture.
Data Source
AI summary
Propeller assemblies, aircraft including the same, and associated methods. A propeller assembly includes a first propeller and a second propeller operatively coupled to a coupling shaft and configured to pivot with respect to one another about a propeller rotation axis. The propeller assembly additionally includes a coupling assembly operatively coupled to the first propeller and the second propeller and configured to transition between a plurality of pivotal configurations defined between and including a stowed configuration and a deployed configuration. The coupling assembly transitions from the stowed configuration toward the deployed configuration when a coupling assembly rotational velocity rises above a threshold stowed rotational velocity. In examples, an aircraft includes one or more propeller assemblies operatively coupled to a fuselage. In some examples, a method of operating a propeller assembly includes automatically transitioning a coupling assembly of the propeller assembly between a stowed configuration and a deployed configuration.