Hydraulic Components Contribution to Total Power Losses and Acceleration of an Open Loop System With Long Hose

This paper is concerned with forest logging machinery. A great deal of final felling in cut-to-length method done by harvester, which fells, delimbs and cuts the trees to pre-selected lengths. Two important criteria of a harvester head are that it has to be energy efficient and it has to be as fast as possible. To minimize losses in hydraulic systems the main demand is to reduce pressure losses in high power valves and outer components as much as possible. Each orifice in the flow path results in power losses. This work is an experimental study on power losses and acceleration of hydraulic motor in a system with long hoses. Main hydraulic components included are hydraulic pump, cartridge valve, pipe line and hydraulic motor. The results show that pre-activating the pump improves the system speed. To reduce losses, optimization of valve block, cartridge valve orifices are needed. Accumulators are favourable if combined with high stand-by pressure.