Decentralised Hydraulics II

  System Model of an Electro-Hydraulic Compact Axle (EHA) Copyright: © MSE


Georg Hartmann © Copyright: MSE


+49 241 80 90848


In mobile working machines, such as excavators, the hydraulic power is usually provided by a central pressure supply via one or more pumps in the vehicle. A valve is used to centrally control the actuators that are connected to the pressure supply via hoses and pipelines. The central pressure supply and valves, as well as the hoses and pipes, cause losses that reduce the efficiency. Decentralised hydraulic systems, in which each actuator has a separate pressure supply, promise an increase in efficiency with short pipes and efficient controlling. In the context of the electrification of mobile working machines, electro-hydraulic compact axes (EHA) allow a powerful pressure supply with increased efficiency. In a previous project, a corresponding EHA was successfully realised with high-speed components (motor and internal gear pump) with regard to a small installation space. However, the currently existing EHA concepts are still too big and too heavy to be used in mobile working machines.

Research goals

Within the framework of the research project Decentralised Hydraulics II, the further development of the EHA is planned in order to increase the power density. By reducing the installation space and weight, the attractiveness for the use in mobile working machines should be promoted. On the one hand, this will be achieved through the reversibility of the high-speed components and the resulting savings in controlling elements. On the other hand, an increased degree of functional integration of the components should contribute to this. An integral product architecture with high power density will be developed via systematic and model-based function and component integration. For this purpose, possible system architectures of the EHA, consisting of functional, principle solution and product structures, will be modelled, analysed and optimised with regard to weight, installation space and costs. For this purpose, the system architecture will be connected with corresponding models for determining weight, installation space and costs. Additionally, the potential of generative design and topology optimisation for a further increase in power density will be investigated.


01.05.2022 - 31.10.2024


Funded project partners:

  • Institute for Fluid Power Drives and Systems (IFAS) at the RWTH Aachen University

Associated project partners:

  • Volvo Contruction Equipment Germany GmbH
  • Komatsu Hanomag GmbH
  • Bauer Maschinen GmbH
  • Fluitronics GmbH
  • Eckerle Industrie Electronik GmbH
  • Wilhelm Hoven Maschinenfabrik GmbH & Co
  • Bruno Volkmann Elektromaschinenbau GmbH
  • Fluidon Gesellschaft für Fluidtechnik mbH
  • IST GmbH
  • Lasco Umformtechnik GmbH
  • Sander Messtechnik GmbH

Project funded by:

  • Federal Minitry for Economic Affairs and Climate Actions

  AiF - FKM

Project promoted by:

  • Forschungskuratorium Maschinenbau e.V. – FKM (AiF)