Integrated Electric Propulsion Unit With Unified Cooling and Control
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Solution Overview
Problem
Conventional electric propulsion systems for aircraft are complex and costly due to their federated component design, which requires separate mechanical, cooling, and electrical interfaces, making integration within the nacelle challenging and inefficient.
Innovation Solution
An integrated electric propulsion unit with a simplified cooling system and reduced number of electrical connections, where all components share a single circuit and are housed within a nacelle, optimizing weight and cost by eliminating separate housings and interfaces.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If federated components (separate motor, inverter, transmission) are used, then each component can be designed independently with optimized performance, but the system complexity increases due to extensive mechanical, cooling, and electrical interfaces
Solution Approach 1:
The patent combines the motor, inverter, and transmission into a single integrated electric propulsion unit housed within one nacelle. The inverter is positioned adjacent to the motor with direct mechanical and thermal coupling, eliminating the need for separate housings, cooling circuits, and electrical interfaces that would exist in a federated configuration. This merging reduces system complexity while maintaining component performance through optimized internal arrangements.
Solution Approach 2:
The integrated nacelle serves multiple functions simultaneously: it houses the motor, inverter, and transmission; provides a unified cooling circuit for all components; serves as the structural mounting point; and contains the control electronics. This multi-functionality eliminates the need for separate dedicated structures for each function, reducing overall system complexity.
2Temperature
If separate cooling circuits are used for each component, then each component can be optimized for its specific thermal requirements, but the number of cooling interfaces and system complexity increases
Solution Approach 1:
The patent implements a single unified cooling circuit that serves the motor, inverter, and transmission simultaneously. The cooling system uses a common coolant flow path with strategically positioned heat exchangers that can manage the thermal requirements of all components through a single integrated loop, eliminating the need for multiple separate cooling circuits and their associated pumps, valves, and piping.
3Reliability
If multiple separate housings are used for motor and inverter, then each component can be protected and maintained independently, but the weight and installation complexity increase
Solution Approach 1:
The patent uses a single integrated nacelle housing that contains the motor, inverter, and transmission together. This eliminates the weight of multiple separate housings and their associated mounting structures, fasteners, and sealing systems. The unified housing is designed to provide adequate protection for all components while reducing overall weight compared to a federated configuration with separate protected enclosures.
4Ease of operation
If extensive electrical interfaces and control harnesses are used, then each component can be controlled and monitored independently, but the number of electrical connections and installation complexity increase
Solution Approach 1:
The patent positions the inverter adjacent to the motor with direct electrical coupling, eliminating long electrical harnesses and multiple connection points. The control electronics are integrated within the same nacelle, allowing for localized signal routing and reduced wiring complexity. This arrangement maintains independent control capability while significantly reducing the number of electrical interfaces and harness complexity.
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
The integrated system simplifies integration, reduces weight and cost, and improves efficiency by combining power train components into a single entity, enabling easier installation and maintenance while minimizing interfaces and optimizing thermal and electrical connections.
Implementation Method 1
a cooling circuit configured to guide a flow of circulating liquid... The cooling circuit comprises: a sump mounted to the housing; a cooling pump mounted to the housing, geared to the motor shaft, and in fluid communication with the sump; and a cooling channel disposed inside the housing and connected to guide the circulating liquid from the cooling pump along a flow path toward the sump
Implementation Method 2
an AC motor disposed within the housing and comprising a plurality of bearings supported inside the housing, a hollow motor shaft rotatably coupled to the housing by the plurality of bearings, a stator which is supported by the housing, and a rotor which is mounted to the hollow motor shaft
Implementation Method 3
an inverter disposed within the housing and connected to receive DC power for conversion into AC power
Data Source
AI summary
An electric propulsion unit comprising a housing, an AC motor, a beta rod, a propeller, a governor, an inverter, and a controller. The AC motor is disposed within the housing and includes bearings supported inside the housing, a hollow motor shaft rotatably coupled to the housing by the bearings, a stator which is supported by the housing, and a rotor which is mounted to the hollow motor shaft. The beta rod is axially translatable inside the hollow motor shaft. The propeller is mechanically coupled to the hollow motor shaft. The propeller includes propeller blades having an adjustable pitch angle which depends on an axial position of the beta rod. The governor is configured to adjust a pitch angle of the propeller blades by actuating axial translation of the beta rod. The controller is disposed inside the housing and configured to control the pitch angle of the propeller blades.