Hubless Electric Fan With Offset Motor Axis for Aircraft Thrust
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Solution Overview
Problem
Commercial aircraft propulsion systems, particularly gas turbine engines, continue to emit pollutants and generate noise, necessitating further improvements in efficiency and environmental impact.
Innovation Solution
The development of an electric fan system with a hubless rotor and roller bearings, where the motor rotation axis is radially offset from the fan rotation axis, allowing for counter-rotation and efficient power distribution through multiple electric motors, enabling quieter and more environmentally friendly operation, and the ability to generate electricity during windmilling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If gas turbine engines are used for aircraft propulsion, then thrust and power are achieved, but emissions and noise are generated
Solution Approach 1:
The patent replaces the gas turbine engine's combustion-based power generation system with an electric motor system. The electric motor directly drives the fan without combustion, eliminating emissions and noise from the engine while maintaining thrust generation capability through electromagnetic force conversion of electrical energy to mechanical rotation.
Solution Approach 2:
The fan assembly is designed to serve multiple functions: it generates forward thrust during flight, provides reverse thrust for braking by rotating in opposite direction, and can operate in windmilling mode to generate electricity during descent. This multi-functionality replaces the need for separate systems like conventional thrust reversers.
2Force
If conventional thrust reversers are used, then reverse thrust is achieved for braking, but device complexity increases
Solution Approach 1:
The same electric motor and fan assembly that generates forward thrust is used to generate reverse thrust by simply reversing the motor's rotation direction. This eliminates the need for separate thrust reverser mechanisms, reducing device complexity while maintaining the reverse thrust capability for aircraft braking.
3Ease of manufacture
If hubless rotor design is implemented, then manufacturing and maintenance are simplified, but bearing configuration complexity increases
Solution Approach 1:
The rotor assembly is divided into multiple independent blade elements mounted on a hubless structure, with roller bearings distributed around the circumference. This segmentation allows each blade to be manufactured and replaced independently, simplifying maintenance while the distributed bearing arrangement manages the mechanical loads without requiring a complex centralized hub structure.
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 reduces noise and emissions, maintains performance across altitudes, and eliminates the need for conventional thrust reversers, offering comparable thrust levels to turbofan engines while lowering maintenance and operational costs.
Implementation Method 1
The fan may comprise a plurality of roller bearings mounted to the stator. Each roller bearing may have an axis of rotation that is non-parallel to the fan rotation axis.
Implementation Method 2
allowing windmilling of the bladed rotor, and generating electricity from the windmilling of the bladed rotor
Data Source
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AI summary
An electric fan (12) for producing thrust to propel an aircraft (10) is disclosed. The electric fan (12) comprises a stator (22), a fan rotor (24) rotatably mounted relative to the stator (22) and an electric motor (26) mounted to the stator (22) and drivingly engaged with the fan rotor (24) to cause rotation of the fan rotor (24) relative to the stator (22). The fan rotor (24) comprises an annular body (28) defining a flow passage therethrough and a plurality of fan blades (30) disposed in the flow passage and mounted for common rotation with the annular body (28) about a fan rotation axis (FA). The electric motor (26) has a motor rotation axis (MA) that differs from the fan rotation axis (FA).