Engine Core Electric Machine Layout for Compact Gas Turbines

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Solution Overview

Problem

There is a need for arrangements and systems that facilitate the integration of electric motors and generators within the core of a gas turbine engine to reduce the overall size of the engine.

Innovation Solution

The integration of an electric machine, comprising an electric machine rotor and stator, is arranged within the engine core, with the rotor being rotatable between the compressor and turbine rotors, and the combustor is positioned radially outboard and circumferentially about the electric machine, allowing for a compact configuration that reduces the engine's size.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of moving object

If the electric motor and electric generator are connected to a gearbox outside of the engine core, then the engine core structure is simpler, but the overall size of the gas turbine engine is larger

Engineering Contradiction:
Improveoverall size of gas turbine engineVSAvoidengine core structure
Core Design Contradiction:
Volume of moving objectVSDevice complexity

Solution Approach 1:

The electric machine is nested within the engine core by positioning the electric machine rotor between the compressor rotor and turbine rotor, with the combustor arranged radially outboard and circumferentially about the electric machine. This nesting arrangement allows the electric machine to occupy space within the existing engine core structure, reducing the overall engine size while integrating multiple components in a compact configuration

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

The combustor is positioned radially outboard and extends circumferentially about the electric machine, utilizing the radial dimension to accommodate both the electric machine and combustor within the engine core. This dimensional arrangement allows the electric machine rotor to rotate on one axis while the combustor surrounds it radially, enabling compact integration without interfering with the rotational flowpath

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Volume of moving object

If the electric machine is arranged within the engine core, then the overall size of the engine is reduced, but the arrangement and integration become more complex

Engineering Contradiction:
Improveoverall size of engineVSAvoidintegration of electric machine
Core Design Contradiction:
Volume of moving objectVSEase of manufacture

Solution Approach 1:

The engine is segmented into distinct rotating structures: the compressor rotor, electric machine rotor, turbine rotor, and shaft, with each component having its own bearing support. This segmentation allows for modular assembly and manufacturing of the electric machine within the engine core, as each component can be manufactured and tested independently before integration

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Bearings are introduced as intermediary components to support both the shaft and electric machine rotor, facilitating their rotation and integration within the engine core. The bearings act as mediators that enable the electric machine to be mounted within the core structure while maintaining proper rotational support and alignment

Inventive Principle:
Principle #24Intermediary (Mediator)

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 enables a reduction in the overall size of the gas turbine engine by utilizing the space within the engine core for the electric machine, while maintaining its functionality as both a motor and generator, and includes a lubrication system to support the bearings and electric machine components.

Implementation Method 1

The electric machine may be configurable as an electric motor during a motor mode of operation. The electric machine may also or alternatively be configurable as an electric generator during a generator mode of operation.

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

The assembly may also include a plurality of bearings. These bearings may rotatably support the shaft. The bearings may include a first bearing and a second bearing.

Methodology Applied
Scientific EffectLubrication: Lubrication

Data Source

PatentEP4286657A1Gas turbine engine with electric machine in engine core
Publication Date: 2023.12.06 PRATT & WHITNEY CANADA CORP
  • EP4286657A1 patent drawingFigure 1
  • EP4286657A1 patent drawingFigure 2
  • EP4286657A1 patent drawingFigure 3

AI summary

A gas turbine engine (20) assembly includes an engine core (24) and an electric machine (26). The engine core (24) includes a first rotating structure (32A), a second rotating structure (32B), a combustor (64) and a flowpath (60). The first rotating structure (32A) includes a first structure turbine rotor (40A). The second rotating structure (32B) includes a second structure compressor rotor (38B), a second structure turbine rotor (40B) and a second structure shaft (42B) connecting the second structure compressor rotor (38B) to the second structure turbine rotor (40B). The second structure compressor rotor (38B), the combustor (64), the second structure turbine rotor (40B) and the first structure turbine rotor (40A) are arranged sequentially along the flowpath (60). The electric machine (26) is arranged within the engine core (24). The electric machine (26) includes an electric machine rotor (70) and an electric machine stator (72) adjacent the electric machine rotor (70). The electric machine rotor (70) is rotatable with the second rotating structure (32B) and located between the second structure compressor rotor (38B) and the first structure turbine rotor (40A).