Electrohydraul­ic compact drives for low power applications

Research Task/Objectives

Nowadays, hydraulic linear drives are rarely used in low power applications. Reasons are
the increased effort on installation, space requirement and maintenance as well as the
high power losses of conventional valve controlled drives.
Goal of this investigation is the development of electrohydraulic compact drives, which feature the advantages of hydraulic drives (reliability, large forces, good overload protection) as well as good energy-efficiency, less required space, low maintenance effort and easy plug and play connectivity at the same time. Thus, for the use in low power applications the attractiveness of hydraulic drives is increased significantly.

Approach/Results

Designed as turn-key assembly, electrohydraulic compact drives provide defined  electrical and mechanical interfaces only. With the use of a speed variable displacement
control, inherent throttle losses are minimized and the efficiency is increased significantly – in particular under part load. Existing variants of controlling a single rod cylinder directly with the pump were investigated and evaluated systematically. Preferred variants were built up as demonstrator and investigated by means of simulation and experiment. In comparison with an electromechanical compact drive, the static and dynamic performance as well as the energy-efficiency of the demonstrators could be shown.

© S. Michel