Inductively-Energized Propeller Hub for Rapid Pitch Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional propeller hubs face challenges such as added weight, bending moment, and vulnerability to destructive resonant vibration due to propeller shaft extensions, and they rely on hydraulic fluid pressure or carbon brushes for energy and signal transfer, which are prone to wear and maintenance issues, limiting the speed and reliability of propeller pitch changes, especially in quiet and agile electric aircraft.
Innovation Solution
An electric, inductively-energized, multi-bladed propeller hub with an internal battery and reversible hubmotor, utilizing Faraday's Law of Induction for wireless energy and signal transfer across an air gap, eliminating the need for propeller shaft extensions and carbon brushes, and enabling near-instantaneous modulation of thrust, lift, and drag through precise pitch control of each blade.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Shape
If propeller shaft extensions are used to attach propeller hub to engine, then streamlined nacelle design is improved, but weight increases and vulnerability to resonant vibration worsens
Solution Approach 1:
The patent removes the propeller shaft extension from the system by directly coupling the propeller hub to the electric propmotor flange. This extraction eliminates the source of resonant vibration and weight penalty while maintaining streamlined nacelle design through close apposition of hub and motor.
Solution Approach 2:
The patent merges the propeller hub and propmotor into a closely coupled assembly with minimal spacing. The hub mounting flange is positioned in close apposition to the propmotor flange, creating an integrated unit that eliminates the need for shaft extensions and reduces overall weight.
2Use of energy by moving object
If carbon brushes and slip rings are used to transfer electrical energy to rotating propeller hub, then power transmission is achieved, but reliability decreases due to wear and friction
Solution Approach 1:
The patent replaces the mechanical carbon brush and slip ring system with an inductive coupling system. Electrical energy is transferred wirelessly through electromagnetic induction across an air gap between the rotating hub and stationary propmotor, eliminating mechanical contact and associated wear.
Solution Approach 2:
The patent introduces electromagnetic fields as an intermediary to transfer electrical energy between the stationary propmotor and rotating propeller hub. The inductive coupling system uses magnetic flux as a mediator to pass power without direct physical contact.
3Ease of operation
If hydraulic fluid pressure systems are used to actuate propeller pitch changes, then pitch control is achieved, but speed of pitch change is limited by fluid flow through orifices
Solution Approach 1:
The patent replaces hydraulic actuation with an electric motor-driven actuation system. The motor directly drives the pitch control mechanism through electrical power delivered via inductive coupling, eliminating fluid flow constraints and enabling much faster pitch changes.
Solution Approach 2:
The patent employs rapid cyclic electrical actuation to achieve quick pitch changes. The electric motor can rapidly reverse direction and adjust pitch angle without the inertial constraints of hydraulic systems, enabling high-speed pitch modulation for agile flight control.
4Ease of operation
If quill shafts are used to operate actuators inside propeller hub, then pitch actuation is achieved, but device complexity and weight increase
Solution Approach 1:
The patent extracts and removes the quill shaft mechanism from the propeller hub. Instead, pitch actuation is achieved through a simpler electric motor-driven system with direct mechanical coupling, eliminating complex rotating shafts and associated bearings.
Solution Approach 2:
The patent replaces the mechanical quill shaft actuation system with an electric motor-driven system. Electrical power is delivered wirelessly via inductive coupling to drive the motor, which directly actuates the pitch control mechanism without requiring rotating shafts penetrating the hub.
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
This solution provides reliable, rapid, and precise control of propeller pitch, enhancing the agility and quiet operation of electric aircraft by delivering substantial electrical power for instantaneous changes in thrust, lift, and drag, while reducing maintenance needs and weight, thus improving safety and operational efficiency.
Implementation Method 1
An electric, inductively-energized, multi-bladed, controllable-pitch propeller hub whose internal battery, electronic control unit and electric hubmotor, when energized by a voltage inducted into an annulus of receiver coils that is mounted onto said propeller hub
Data Source
AI summary
An electric, inductively-energized, multi-bladed, controllable-pitch propeller hub is configured with an internal battery, electronic control unit and electric internal reversible hubmotor, when energized by a voltage inducted across an air gap into an annulus of receiver coils that is mounted onto said propeller hub and when said propeller hub is attached to and operated with complementary electrical, electronic and mechanical components that enable wireless command signals, together forming a novel and versatile device whose operation can provide near-instantaneous modulation of aircraft thrust, lift and drag by the action of said propeller hub to actuate precise and equal changes to the pitch of each propeller blade through a full range of useful pitch settings, both during rotation of said propeller hub and when said propeller hub is stationary, with an innovation including a coaxial driveshaft that facilitates the removal and installation of said propeller hub from a propmotor.