Comparison of packaging hydraulic and electric components in a HEV power line

Scientific papers usually do not present ‘lessons learnt’ results, what comes to engineering aspects in vehicle design. A lot of valuable information is collected during research and prototyping projects, but this is not shared in public often enough. This paper is a general discussion about the engineering matters related to the implementation of hybrid systems in mobile work machines. The target of this paper is to underline the importance of paying attention of these matters already in very beginning of the research and development.
The discussed aspects are related to the energy transmission, packaging of components, vehicle assembly and service. The energy transmission section compares benefits and drawbacks of hydraulic and electric transmission implementations. Packaging of components presents some issues to pay attention to when accommodating components into vehicle. Service aspect highlights the benefits and drawbacks of different solutions in maintenance operations.
The discussion is limited to explain only differences and analogies between hydraulic and electric components. The cost factors can be estimated only by the reader, because they are very case sensitive. The key factor is number of machines made in serial production. In case of passenger cars the cost structure is very different compared to small series mobile work machines.