Development of an APU Gearbox Clutch Control System for Use in Cold Climates and with High Power Density

This paper describes the analysis, design and development carried out to engineer a compact 300 Horsepower 12,000 rpm, wet clutch system capable of operating reliably and repeatedly over a very wide range of operational conditions. The descriptions include the innovations in electro hydraulic servo control, clutch cooling and protection, and control algorithms. It demonstrates the value of understanding and working on the system as a whole rather than the control algorithms alone to obtain the requisite result.