Direct Actuation of Large Sized Valves by a Hydraulically Relieved Electromechanical Actuation System


  • Tobias Vonderbank Institute for Fluid Power Drives and Systems (ifas), RWTH Aachen University, Aachen, Germany
  • Pierre Marc Laßl Chavez Institute for Fluid Power Drives and Systems (ifas), RWTH Aachen University, Aachen, Germany
  • Katharina Schmitz Institute for Fluid Power Drives and Systems (ifas), RWTH Aachen University, Aachen, Germany



Electromechanical actuation system, Large sized valves, Valve actuation system, Pilot operation, Flow controlled system


Extensive actuation forces and strokes are required for the actuation of large sized valves normally implemented in high power hydraulic systems. A hydraulically piloted operation is, for now, the most suitable solution and state of the art. However, there are some applications where electromechanical valve actuation systems are at advantage against common pilot operation systems. In this contribution it is analyzed in which cases the application of electro-mechanical actuators can be of advantage and why displacement-controlled systems may be one of these applications. A novel electromechanical valve actuation system for large sized 4/3-way directional control valves for the use in displacement-controlled systems is presented. This new actuation system is characterized by a hydraulic relief of the centering springs. Therefore, the springs are only active in safety-critical conditions, such as a power outage. Since the actuator is not working against the spring force during every displacement, the necessary actuation force is reduced drastically. Thus, common electromechanical actuators can be used. In case of a power outage, the spring relief is deactivated causing the stored energy to center the spool in its neutral position. The performance of the novel actuation system is examined through measurements conducted on a manufactured demonstrator for valves of nominal size 25 with a flow rate of up to 600 l/min.


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Author Biographies

Tobias Vonderbank, Institute for Fluid Power Drives and Systems (ifas), RWTH Aachen University, Aachen, Germany

Tobias Vonderbank received the bachelor of engineering from Hochschule Niederrhein University for Applied Sciences in 2016, and the master of Science from RWTH Aachen University in 2018. He is currently working as Research Associate at Institute for Fluid Power Drives and Systems, RWTH Aachen University. His research areas are Fluid Power, valves and electromechanical valve actuation systems.

Pierre Marc Laßl Chavez , Institute for Fluid Power Drives and Systems (ifas), RWTH Aachen University, Aachen, Germany

Pierre Marc Laßl Chavez acquired the Bachelor of Engineering from the RWTH Aachen University in 2021. He is currently working as a student Assistant in the field of electromechanical valve actuation systems at the Institute for Fluid Power Drives and Systems at RWTH Aachen University.

Katharina Schmitz , Institute for Fluid Power Drives and Systems (ifas), RWTH Aachen University, Aachen, Germany

Katharina Schmitz graduated in mechanical engineering at RWTH Aachen University in 2010 with part of her studies taking place at Carnegie Mellon University in Pittsburgh (USA) and working in Le Havre (France). After graduation, she worked as a scientific staff member and Deputy Chief Engineer at IFAS, the Institute for Fluid Power Drives and Controls of Prof. Murrenhoff. In 2015, Prof. Schmitz graduated as Dr.-Ing. and started working in the industrial sector for a family-owned company, which focuses on special purpose hydraulic solutions and large cylinders. There, she was promoted to Technical Director in 2016. Since March 2018 she is full professor at RWTH Aachen university and Director of ifas, the Institute or Fluid Power Drives and Systems.


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SICFP 2021