The Be-Rex Engine-Generator: A Revolutionary Two-Stroke, Lightweight and Cost-Efficient Singular Unit



WCX SAE World Congress Experience
Authors Abstract
Although electricity is necessary for a country's economic development, many countries lack suitable grid infrastructure. Portable generators offer a consistent electric supply in the event of a blackout.
Be-Rex B.V. develops and already assembled a revolutionary engine-generator prototype. It eliminates the use of camshafts, crankshafts and flywheels while integrating the generator parts into the same spherical housing. Thus, it constitutes a compact, lightweight and cost-efficient singular unit. There is no mechanical power output while the load of the engine is determined by the demanded load of the generator. The four combustion chambers are arranged in pairs on the north and south hemisphere and the magnets of the stator are placed circumferential at the equator of the spherical housing. The rotating disc and the joiner build the rotor of the generator. While developing the engine special emphasis has been put on its multi-fuel capability. Optimized gas exchange together with an efficient scavenging concept and the combustion system allow the atmospheric version of the prototype with a displacement volume of 400 cc to achieve 10 bar of indicated mean effective pressure (imep) when running on gasoline. Using 1-D WAVE simulations the same atmospheric version converted to ammonia fuel achieves 8 bar of imep.
First firing results of an engine generator prototype running on gasoline solidify the proof of concept. In the design section the main characteristics of the concept will be highlighted and the working principle will be explained. In the modelling approach section the methodology to tackle the leakage and the friction issues will be presented before the main results of the final design optimization will be discussed. Afterwards, the first experimental runs will be analyzed and finally some possible applications will be addressed.
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Bekking, P., Puts, G., Spiller, M., and Bikas, G., "The Be-Rex Engine-Generator: A Revolutionary Two-Stroke, Lightweight and Cost-Efficient Singular Unit," SAE Technical Paper 2023-01-0399, 2023,
Additional Details
Apr 11, 2023
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Technical Paper