Counter-Rotating Propeller De-Icing via Integral Bearing Generator

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Solution Overview

Problem

Existing de-icing systems for aircraft propeller blades face challenges in efficiently transferring electric power to rotating blades, particularly in counter-rotating systems, due to high wear and power losses through slip ring and brush interfaces, requiring frequent maintenance.

Innovation Solution

A self-contained counter-rotating turbo prop system with an integral bearing/generator assembly using permanent magnets and coil assemblies to generate electric power for de-icing, eliminating the need for slip ring and brush connections by producing power within the propeller system.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If a slip ring and brush combination is used to transfer electric power to rotating propeller blades, then electric power can be delivered to the blades, but the system experiences high wear requiring continual maintenance and monitoring

Engineering Contradiction:
Improveelectric power deliveryVSAvoidmaintenance requirements
Core Design Contradiction:
Use of energy by moving objectVSReliability

Solution Approach 1:

The patent extracts the power generation function from the stationary airframe and integrates it directly into the rotating propeller hub. The generator is mounted on the propeller shaft within the hub, allowing the propeller blades to generate their own de-icing power while rotating, eliminating the need for external power transfer through slip rings and brushes.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The propeller system becomes self-sufficient by generating its own electric power for de-icing through the integrated generator. The generator uses the rotational motion of the propeller shaft itself to produce electricity, allowing the system to service itself without external power transfer mechanisms that require maintenance.

Inventive Principle:
Principle #25Self-service

2Use of energy by moving object

If a slip ring and brush combination is used to transfer electric power to rotating propeller blades, then electric power can be delivered to the blades, but power losses occur through the slip ring and brush interface

Engineering Contradiction:
Improveelectric power deliveryVSAvoidpower losses
Core Design Contradiction:
Use of energy by moving objectVSLoss of energy

Solution Approach 1:

The patent eliminates the intermediate power transfer interface (slip rings and brushes) by extracting the power generation function and placing it directly on the rotating propeller shaft. This removes the source of power losses at the interface between stationary and rotating components.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent replaces the mechanical electrical contact system (slip rings and brushes) with an electromagnetic generation system. The generator converts mechanical rotation directly into electrical power, eliminating the need for sliding electrical contacts and their associated energy losses.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Reliability

If an integral generator is integrated into the bearing/generator assembly for power generation, then maintenance needs are reduced, but the device complexity increases

Engineering Contradiction:
Improvemaintenance needsVSAvoidassembly complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent combines the bearing assembly and generator into a single integrated unit. The generator is mounted directly on the propeller shaft within the bearing housing, merging two previously separate functions (support and power generation) into one unified assembly that reduces overall system complexity.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The bearing/generator assembly performs multiple functions simultaneously: it provides mechanical support for the propeller shaft through bearings, generates electrical power for de-icing through the generator, and houses both components in a single integrated structure. This multi-functionality reduces the number of separate components and simplifies maintenance.

Inventive Principle:
Principle #6Universality (Multi-functionality)

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

The solution effectively powers de-icing elements on propeller blades, reducing maintenance needs and power losses, while enabling efficient ice removal through generated heat, and allows for simultaneous pitch adjustment of propeller blades.

Implementation Method 1

The bearing/generator assembly includes a plurality of permanent magnets and coil assemblies separated by an air gap. Relative rotation between first and second parts of the bearing/generator assembly provides for the generation of electric power.

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

Each of the propeller blades includes a heating element that provides a de-icing function. The electric power created by the bearing/generator assembly provides the electric energy required to drive the heating elements mounted to the first and second pluralities of propeller blades.

Methodology Applied
Scientific EffectResistive heating: Joule Heating

Data Source

PatentEP2562085B1De-icing system for modular counter rotating propeller
Publication Date: 2017.10.04 HAMILTON SUNDSTRAND CORP
  • EP2562085B1 patent drawingFigure 1
  • EP2562085B1 patent drawingFigure 2~3
  • EP2562085B1 patent drawingFigure 4

AI summary

A self-contained counter rotating turbo prop system (14) includes a power generating system that produces electric power for a de-icing system. A bearing/generator assembly (80) includes a plurality of permanent magnets (108) and coil assemblies (110) separated by an air gap (116). Relative rotation between first and second parts (82, 84) of the bearing/generator assembly (80) provides for the generation of electric power utilized to drive the heating elements (48, 50) mounted to the propeller blades (18, 20).