Aircraft Cabin Blower Transmission With Dual-Input Speed Control
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Solution Overview
Problem
Cabin blower systems in aircraft face limitations in mechanical driving, particularly due to architectural constraints such as size and weight, and the need for variable speed control to maintain consistent cabin air flow and pressure regardless of engine operating points and ambient conditions.
Innovation Solution
An aircraft cabin blower system utilizing a transmission with a power management system and dual electrical machines, allowing for mechanical power conversion between the gas turbine engine and compressor, enabling variable speed control and dual-mode operation for both blower and starter functions, with an epicyclic gearbox and power storage for efficient energy management.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If mechanical driving of the compressor is employed from the gas turbine engine, then the compressor can be driven directly by engine power, but architectural constraints such as size and weight are introduced
Solution Approach 1:
The patent replaces the traditional mechanical drive system (accessory gearbox and transmission) with an electrical drive system. The gas turbine engine drives a generator that produces electrical power, which then drives an electric motor connected to the compressor. This substitution eliminates the need for heavy mechanical transmission components while maintaining the power delivery function, directly resolving the contradiction between providing sufficient compressor drive power and reducing system weight.
2Adaptability or versatility
If a gearing mechanism such as a continuously variable transmission is provided to vary the speed of drive delivered to the compressor, then variable speed control is achieved, but the system size and complexity increase
Solution Approach 1:
The patent replaces the mechanical continuously variable transmission (CVT) with an electrical speed control system. The generator and motor combination, controlled by a power management system, provides variable speed control to the compressor without requiring complex mechanical gearing mechanisms. The electrical system achieves the same adaptability function with significantly reduced mechanical complexity.
3Power
If mechanical driving of the compressor is employed, then direct power transfer from the engine is achieved, but the locations at which drive can be taken from the engine are limited
Solution Approach 1:
The patent replaces the mechanical power transfer system with an electrical power system. The generator can be positioned at various locations on the engine, and electrical power can be transmitted flexibly to the motor-compressor assembly. This electrical architecture provides much greater location flexibility compared to mechanical drive systems, which are constrained by the need for direct mechanical coupling and alignment.
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 solution provides flexible speed control for the cabin blower compressor, reduces architectural constraints, and facilitates efficient engine starting through combined mechanical and electrical power management, enhancing operational flexibility and efficiency.
Implementation Method 1
the first electrical machine is configured to receive mechanical power from the gas turbine engine and act as a generator to provide electrical power to the power management system
Implementation Method 2
the second electrical machine is configured to act as a motor providing mechanical power to the transmission in the form of a second transmission input, the second electrical machine being driven by electrical power from the power management system
Data Source
AI summary
An aircraft cabin blower system includes a transmission configured to receive mechanical power from a gas turbine engine in the form of a first transmission input; and an electrical circuit including a first electrical machine, a second electrical machine, and power management system, wherein, when operating in a blower mode, the first electrical receives mechanical power from the gas turbine engine and act as a generator to provide electrical power to the power management system, and the second electrical machine acts as a motor providing mechanical power to the transmission in the form of a second transmission input, the second electrical machine being driven by electrical power from the power management system. The transmission's output drives a cabin blower compressor when operating in the blower mode, a speed of the output of the transmission being determined by a function of a speed of the first and second transmission inputs.