Progress in Marine Hybrid Propulsion Drive Systems

The paper provides an overview of current marine hybrid propulsion drive solutions, focusing on a particular device for engaging and disengaging the electric motor or diesel engine on the same propeller shaft line. The coupling system is controlled by an overrunning clutch (freewheel type) with ball bearings, allowing a fast change in diesel or electric propulsion mode during sailing. Moreover, it does not require any electronics, limiting maintenance to occasional oil changes. In the examined case study the freewheel working principle is applied to the hybrid propulsion of a pleasure craft, achieving a more compact and lower cost powertrain.