Integrated Accessory Gearbox Layout for Compact Electric Machine Packaging
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Solution Overview
Problem
Current accessory gearboxes in aircraft turbomachines face challenges in accommodating electric machines in a compact space, leading to increased axial dimensions and complexity in assembly.
Innovation Solution
The proposed accessory gearbox integrates an electric machine within its casing, utilizing the internal volume to house the machine, where the rotor is supported by a shaft and the stator extends around the rotor within the enclosure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If electric machine equipment is added to the accessory gearbox, then the functional capability is improved, but the overall dimensions and axial length increase
Solution Approach 1:
The electric machine is nested within the accessory gearbox casing by utilizing the internal volume around the hybridization pinion shaft. The stator is mounted within the enclosure and the rotor is supported by the pinion shaft, creating a compact integrated assembly where the electric machine occupies the internal volume rather than extending axially outward.
Solution Approach 2:
Instead of mounting the electric machine axially on the outer surface of the gearbox, the invention relocates it to the internal volume around the pinion shaft, effectively using the radial and internal space dimension rather than extending in the axial direction. This dimensional repositioning reduces the axial footprint while accommodating the electric machine.
2Adaptability or versatility
If electric machine equipment is added to the accessory gearbox, then the functional capability is improved, but the assembly complexity increases
Solution Approach 1:
The electric machine is merged with the accessory gearbox into a single integrated unit. The stator is mounted within the gearbox enclosure and the rotor is supported by the existing pinion shaft, combining two previously separate components (gearbox and electric machine) into one assembly, thereby simplifying the overall system architecture and reducing assembly complexity.
Solution Approach 2:
The pinion shaft serves multiple functions: it supports the hybridization pinion for gear train operation and simultaneously supports the rotor of the electric machine. This multi-functionality reduces the number of separate components and simplifies the assembly structure by eliminating the need for separate mounting arrangements for the electric machine.
3Shape
If the accessory gearbox is located in the central area of the turbomachine, then the spatial distribution is improved, but the available space is reduced
Solution Approach 1:
The electric machine is nested within the existing gearbox casing volume, utilizing the internal space around the pinion shaft rather than requiring additional external space. This nesting approach allows the electric machine to be accommodated without increasing the overall gearbox dimensions, thereby preserving the compact central location in the turbomachine.
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 allows for a compact integration of the electric machine, reducing the axial space required and simplifying assembly, while maintaining the gearbox's compactness and efficiency.
Implementation Method 1
an electric machine is an electromechanical device based on electromagnetism that converts electrical energy into mechanical energy (motor mode) or, in a reversible manner, enabling the production of electricity from mechanical energy (generator mode)
Data Source
AI summary
An accessory gearbox houses at least one gear train with a series of pinions. The casing has two substantially flat and opposite parallel side walls between which are mounted support shafts for each of the pinions, each of which receives accessories, and which define in the enclosure an internal volume surrounding a shaft supporting at least one hybridization pinion. The gearbox receives at least one electric machine having a rotor and a stator, wherein the rotor of the electric machine is supported by the shaft supporting the hybridization pinion of the gear train, and the stator extends around the rotor in the internal volume.