The Army is in need of a heavy fuel engine with 30-45 kW output and weighing no more than 110 lbs. This engine will drive a hydraulic supply system that will power a legged military robot. Such a small heavy duty engine with such high power density is not available commercially, therefore it needs to be developed. To that end, in this project a commercially available light aircraft diesel engine the baseline engine will be modified to achieve required design specifications. The baseline engine will be a two-stroke opposed piston diesel engine which offers simplicity and good power density to start with. The baseline engine will be converted to a hydraulic free-piston engine which allows direct conversion of combustion power to hydraulic power. This design not only eliminates the hydraulic pump from the system, but also allows the elimination of heavy components such as the crankshaft and the gear train from the baseline engine. Furthermore, the already available hydraulic power will be used to boost the air charge and to drive the fuel system. Finally, the fuel system will contribute to mass reduction and will be capable of using both diesel and JP-8 fuels.
Keywords: Small Diesel, Power Density, Hydraulic Free-Piston Engine, Multi-Fuel Capability, Intensified Fuel System, Digital Hydraulic Control Valves, Opposed Piston Engine, Two-Strok
