Brushless Starter-Generator Single Housing Drop-In Replacement

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Solution Overview

Problem

Brushed starter-generator systems in aircraft require extensive maintenance, are inefficient, unreliable, and costly due to carbon brush wear, sparking, and the need for complex replacements that involve multiple components and lengthy downtime.

Innovation Solution

A brushless starter-generator system integrated within a single housing, featuring a brushless rotating machine and a power control unit, designed to be a direct replacement for brushed systems, with identical mechanical and electrical interfaces, utilizing a synchronous, permanent magnet, or induction machine, and a simplified, miniaturized power control unit to withstand harsh environments and provide efficient engine starting and power generation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If carbon brushes are used in the starter-generator system, then electrical coupling and decoupling is achieved, but brush wear and carbon particles create maintenance needs and environmental hazards

Engineering Contradiction:
Improveelectrical coupling and decouplingVSAvoidbrush wear and maintenance
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The patent removes the carbon brush component entirely from the starter-generator system, replacing it with a brushless design that uses a permanent magnet rotor and stator windings to achieve electrical coupling and decoupling without physical contact, thereby eliminating brush wear and carbon particle contamination

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent replaces the mechanical brush-and-commutator contact system with an electromagnetic field-based system using permanent magnets and windings, substituting mechanical wear-prone components with a reliable brushless electromagnetic coupling mechanism

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

2Ease of repair

If the starter-generator system is integrated within a single housing, then replacement is simplified, but access requirements remain complex

Engineering Contradiction:
Improvereplacement simplicityVSAvoidaccess requirements
Core Design Contradiction:
Ease of repairVSDevice complexity

Solution Approach 1:

The patent combines the motor and generator components into a single integrated housing with unified mechanical and electrical interfaces, allowing the entire assembly to be replaced as one unit rather than requiring separate access to multiple components distributed across the engine nacelle and fuselage

Inventive Principle:
Principle #5Merging (Combining)

3Reliability

If the starter-generator is designed for extended life operation, then reliability improves, but the system must withstand harsh environmental conditions

Engineering Contradiction:
Improveextended life operationVSAvoidenvironmental exposure
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent designs the starter-generator with inherent robustness to withstand harsh environmental conditions including high temperatures, vibrations, and contamination from the outset, using protective housings, sealed bearings, and ruggedized components that preemptively resist environmental degradation rather than relying on maintenance interventions

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

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 brushless system offers extended life, improved reliability, reduced maintenance, and efficient operation in extreme conditions, with the ability to start engines from low battery voltage and generate high torque, while minimizing downtime and environmental hazards.

Implementation Method 1

The starter-generator system functions as an electric motor rotating the shaft to start the engine... Once the engine reaches idle speed, the starter-generator system functions as a generator that converts mechanical power from the moving engine, in the form of shaft rotation, to usable electrical power

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

The apparatus includes a main generator, an exciter generator, and a permanent magnet generator

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Data Source

PatentEP3276800B1Integrated brushless starter generator
Publication Date: 2021.09.01 ASTRONICS ADVANCED ELECTRONIC SYSTEMS CORP
  • EP3276800B1 patent drawingFigure 1
  • EP3276800B1 patent drawingFigure 2
  • EP3276800B1 patent drawingFigure 3

AI summary

A brushless starter-generator system is contained within a single housing 10. The housing 10 has a first end 18 with an opening to receive a drive spline 16 from a motive source and an opposing second end 20. A brushless, rotating, machine 32 is located adjacent the first end 18 and is kinetically connectable to the drive spline 16. A power control unit 34 is adjacent the second end 20 and electrically coupled to the brushless, rotating machine 32. The brushless, rotating machine 32 is selected from the group consisting of a synchronous machine, a permanent magnet machine, and an induction machine. Electrical and mechanical interfaces are identical to a like-rated brushed version for a true "drop-in" replacement capability to facilitate replacements and up-grades.