Specifications
Application
The system is typically mounted directly to the aircraft engines' accessory gearbox and is designed to fit within the extremely confined space of the engine nacelle. It is therefore very compact and lightweight. The EDC could alternatively be mounted remotely and hydraulically driven, depending on the aircraft application.
System Configuration
The EDC's centrifugal compressor is normally driven by a speed-increasing, three-power-path gearbox. A built-in electronic control system monitors performance and operating parameters and operates the inlet throttle vanes and the spill valve. The throttle vanes are used to limit mass flow and torque demand and to control pressure ratio based on aircraft altitude and engine speed. The spill valve is used for surge protection. The control system also modulates lubrication oil flow based upon shaft speed.
Installation
The EDC normally mounts to one of the AND-type mounting pads on the engine accessory gearbox. Typically one EDC is mounted per engine. The mounting can be configured for any shaft or hydraulic drive.
EDC Features
Environment
- Temperature: -65 to 250 °F (-54 to 121 °C)
- Altitude: Sea level to any aircraft altitude
Physical
- Weight: Lightweight to meet gearbox weight and shear load requirements.
- Cube: Compact to mount in very limited space
Performance
Designed for hot and cold conditions at customer pressure ratio and mass flow requirements while observing maximum torque limits.
Gearbox
- Speed increasing, 20:1 ratio (typical)
- Two-stage, three-power-path (typical)
- External oil supply from aircraft engine or internally supplied.
- Spray lubrication of gear meshes and bearings with dry sump scavenge.
Compressor
- Centrifugal geometry
- Titanium (typical)
- Aluminum vaned diffuser
Control System
- Microprocessor controller:
- 80C196 CPU
- ANSI C & Assembler software
- EMI protected
- Throttle vane and spill valve control
- Temperatures, pressures, and shaft speed monitored
- Protective & diagnostic monitoring
- RS422 communications port for diagnostics, calibration, and testing
- Warning light in aircraft cockpit displays fault codes serially
- Fault code, time of fault, & run time logged in EEROM
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