Speed Reducer Layout for Integrated Turboprop Electric Machine
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The integration of a powerful electrical machine into turboprop engines is hindered by increased volume requirements, which complicates its integration within the mechanical speed reducer without impacting the bulk configuration and size constraints.
Innovation Solution
A turbomachine design with an offsetting axis configuration for the input and output pinions and the use of intermediate transmission lines to transmit torque, allowing for the integration of an electrical machine within the speed reducer, reducing radial bulk and maintaining a compact axial size, while enabling a pitch change system and efficient electric machine performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If a powerful electrical machine is integrated into the speed reducer, then electrical power supply capability is improved, but volume requirements increase and integration complexity worsens
Solution Approach 1:
The patent merges the electrical machine with the speed reducer by integrating the rotor inside the output pinion and the stator within the speed reducer housing. This combination allows the electrical machine to share the same spatial envelope as the speed reducer, thereby improving electrical power capability without significantly increasing the overall volume of the assembly.
Solution Approach 2:
The electrical machine components are nested within the existing speed reducer structure. The rotor is positioned inside the output pinion, while the stator is arranged within the speed reducer housing space. This nesting approach enables the electrical machine to utilize the internal voids and spaces already present in the speed reducer, avoiding additional volume increase.
2Power
If the electrical machine volume is increased to provide more power, then power output is improved, but integration within the speed reducer becomes more difficult
Solution Approach 1:
The patent utilizes the radial dimension by positioning the rotor inside the output pinion and arranging the stator windings radially within the speed reducer housing. This dimensional arrangement allows the electrical machine to be integrated in the radial space rather than requiring additional axial length, thereby reducing integration complexity while maintaining power output capability.
3Volume of stationary object
If the speed reducer uses offset pinion axes for compact design, then radial bulk is reduced, but torque transmission complexity increases
Solution Approach 1:
The patent introduces an intermediate gear as a mediator between the input pinion and the output pinion. This intermediate gear simplifies the torque transmission path in the offset pinion configuration by providing a direct meshing connection, thereby reducing the complexity of torque transmission while maintaining the compact radial bulk achieved through offset axes.
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 the integration of an electrical machine without increasing the volume, facilitating the integration of the rotor and improving the performance of the electric machine, while maintaining a compact size and enabling efficient power transmission.
Implementation Method 1
an electrical machine (in engine mode) to the speed reducer in order to provide additional power during the relevant flight phases. It is also possible to use this electric machine (in generator mode) to recover energy or power during certain flight phases.
Implementation Method 2
Gearboxes can be composed of one or more meshing stages. This meshing is ensured in different ways such as by contact, friction or even magnetic fields.
Data Source
Figure 1~2
Figure 3
Figure 4
AI summary
The invention relates to an aircraft turbomachine, comprising: - a speed reducer (4) having an input pinion (40) connected to a power shaft (2) and an output pinion (41) connected to a propeller shaft, and - an electric machine (60) integrated into the speed reducer and configured to supply electrical power to the propeller shaft or to extract mechanical power from the propeller shaft, the electric machine comprising a rotor (61) driven in rotation about an axis coaxial with a longitudinal axis X of the turbomachine and a stator (62) connected to a housing. According to the invention, the input pinion comprises an input shaft (43) offset with respect to an axis of the output pinion, and the speed reducer comprises two substantially parallel intermediate transmission lines capable of transmitting the torque from the input pinion to the output pinion, which is intended to drive the rotor in rotation.