Aircraft Propeller Slip Ring Wear Reduction

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Solution Overview

Problem

The existing electrical power transfer systems in propeller-equipped aircraft, particularly those using slip rings and brush blocks, experience high wear due to environmental factors like fluids and abrasive materials, leading to excessive maintenance needs.

Innovation Solution

The electrical power transfer system is reconfigured with a slip ring assembly connected to an oil transfer tube and a brush block positioned such that its tips extend axially towards the slip ring assembly, with the reduction gearbox located between the brush block and propeller assembly, reducing wear by minimizing exposure to contaminants and allowing for smaller slip rings.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If slip rings are used to transfer electrical power to rotating propeller components, then electrical power can be supplied to deicing components and other rotating components, but high wear occurs in the brush blocks carbon brushes and slip rings due to exposure to fluids and abrasive materials, resulting in excessive maintenance

Engineering Contradiction:
Improveelectrical power transferVSAvoidcomponent wear and maintenance
Core Design Contradiction:
Use of energy by moving objectVSReliability

Solution Approach 1:

The patent extracts the slip ring assembly from the traditional brush block environment by providing a separate sealed housing for the slip rings. This isolation removes the slip rings from exposure to abrasive materials and fluids in the brush block environment, thereby reducing wear and maintenance requirements while maintaining electrical power transfer capability to rotating components

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent introduces a sealed housing as an intermediary barrier between the slip ring assembly and the brush block environment. This housing acts as a protective mediator that prevents direct contact between the slip rings and harmful contaminants, reducing wear on electrical contact components while allowing continuous operation

Inventive Principle:
Principle #24Intermediary (Mediator)

2Use of energy by moving object

If traditional brush block configuration is used with slip rings, then electrical power can be transferred to rotating components, but the size of slip rings increases and exposure to contaminants increases, leading to higher maintenance requirements

Engineering Contradiction:
Improveelectrical power transferVSAvoidslip ring size and maintenance
Core Design Contradiction:
Use of energy by moving objectVSDevice complexity

Solution Approach 1:

The patent extracts the slip ring assembly from the traditional integrated brush block configuration and provides it with a separate sealed housing. This separation allows for optimized slip ring sizing independent of brush block dimensions and protects against contaminants, reducing both size and maintenance complexity

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent segments the electrical power transfer system into distinct sealed modules: a sealed brush block housing and a sealed slip ring housing. This segmentation allows each component to be optimized independently, reduces overall complexity by isolating functions, and minimizes exposure to contaminants for both components

Inventive Principle:
Principle #1Segmentation

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 configuration reduces wear on slip rings and brush block components, minimizing maintenance requirements and protecting them from contaminants, thereby enhancing the reliability and durability of the power transfer system.

Implementation Method 1

a brush block interactive with the slip ring assembly to transfer electrical power to a plurality of lead wires extending from the slip ring assembly to the propeller assembly

Methodology Applied
Scientific EffectElectrical conduction: Conduction (electrical)

Data Source

PatentEP2730506B1Electrical power transfer system for propeller system
Publication Date: 2018.10.17 HAMILTON SUNDSTRAND CORP
  • EP2730506B1 patent drawingFigure 1
  • EP2730506B1 patent drawingFigure 2
  • EP2730506B1 patent drawingFigure 3

AI summary

A propeller system, 10, for an aircraft includes a propeller assembly rotatable about a central axis and a reduction gearbox, 16, operably connected to the propeller assembly via a propeller shaft, 18. An electrical power transfer system is positioned such that the gearbox, 16, is located axially between the electrical power transfer system and the propeller assembly. The electrical power transfer system includes a slip ring assembly operably connected to an oil transfer tube, 24, extending to the propeller assembly and a brush block, 34, interactive with the slip ring assembly to transfer electrical power to a plurality of lead wires extending from the slip ring assembly to the propeller assembly, The brush block, 34, is positioned such that brush block tips, 46, of the brush block, 34, extend toward the slip ring assembly in a substantially axial direction relative to the central axis.