Aircraft Propulsion Gearbox Layout for Axial Space and Accessory Drive
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Solution Overview
Problem
Existing electric aircraft propulsion systems face limitations in efficiency and space constraints, particularly in accommodating the electric motor and accessory loads within the limited axial space of aircraft propulsion systems.
Innovation Solution
The proposed solution involves a gearbox module with a gear assembly and offset gears, an electric motor assembly with a rotor mounted to an offset gear, and accessory load assemblies, where the electric motor drives the gear assembly and propulsor, with the accessory loads being axially coincident with the motor assembly, facilitating efficient propulsion and reliability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If the electric motor and accessory loads are arranged in a conventional configuration, then the propulsion system can operate, but the axial space requirement increases and efficiency decreases
Solution Approach 1:
The patent combines the electric motor assembly and accessory load assemblies into a single integrated propulsion system with a common drive shaft, eliminating the need for separate drive shafts and gearboxes for each accessory load. This merging of functions reduces the overall axial space requirement while improving efficiency by consolidating the drivetrain components.
Solution Approach 2:
The common drive shaft serves multiple functions simultaneously: it drives the propeller for propulsion and also drives all accessory loads (generator, pump, compressor) through directly coupled drive mechanisms. This multi-functionality eliminates the need for separate dedicated drive shafts for each accessory, thereby reducing axial space while maintaining operational efficiency.
2Adaptability or versatility
If the electric motor and accessory loads are arranged in a conventional configuration, then the system can function, but the device complexity increases
Solution Approach 1:
The patent extracts and eliminates the intermediate gearbox components from the conventional multi-shaft configuration. By directly coupling the electric motor to a single common drive shaft and directly coupling all accessory loads to this same shaft, the design removes unnecessary mechanical transmission stages, reducing device complexity while preserving full system functionality.
Solution Approach 2:
The patent merges multiple separate drive shafts and gearboxes into a single common drive shaft system. All accessory loads (generator, pump, compressor) that would traditionally require separate drive shafts and gearboxes are instead directly coupled to the common drive shaft, significantly reducing the number of mechanical components and simplifying the overall device architecture.
3Reliability
If accessory loads are not directly coupled to the drive shaft, then the motor assembly can operate independently, but reliability decreases during power source failure
Solution Approach 1:
The patent establishes preliminary direct mechanical coupling between the common drive shaft and all accessory loads through directly coupled drive mechanisms. This preliminary action ensures that whenever the electric motor operates, all accessory loads are automatically driven without requiring additional control systems or complex coupling mechanisms, thereby ensuring continuous operation and improving reliability.
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 enhances the reliability and efficiency of the propulsion system by allowing operation in a feathering mode and accommodating limited space, ensuring continuous operation of accessory loads even in the event of power source failure.
Implementation Method 1
The electric motor includes a rotor. The rotor is mounted to a first offset gear of the plurality of offset gears. The rotor is configured for rotation about a rotational axis to drive rotation of the gear assembly and output shaft.
Data Source
Figure 1
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AI summary
An assembly for a propulsion system of an aircraft includes a gearbox module (32), an electric motor assembly (28), a first accessory load assembly (24), and a propulsor (34). The gearbox module (32) includes a gear assembly (64) and an output shaft (62). The gear assembly (64) includes a main gear (72) and a plurality of offset gears (74). The electric motor assembly (28) includes an electric motor (38). The electric motor (38) includes a rotor. The rotor is mounted to a first offset gear of the plurality of offset gears (74). The rotor is configured for rotation about a rotational axis to drive rotation of the gear assembly (64) and the output shaft (62). The first accessory load assembly (24) includes at least one first accessory load (84). The at least one first accessory load (84) is mounted to a second offset gear of the plurality of offset gears (74). The propulsor (34) is coupled to the output shaft (62).