Research and development of methods and means to increase energy efficiency of hydraulic drive installations on mobile machinery Reducing energy losses by using “LS” pumps Increasing efficiency of Fluid Power systems by means of digital hydraulics Kinetic and/or potential energy recovery and reuse Financial support and Partners are needed Osijek, 22-23.09.2016

Reducing energy losses by using “LS” pumps Constant Flow Pump Qs-load flow; Qmax-pump flow; ps-load pressure; pmax-safety valve pressure Pu-power used-generates mechanical work: Pu=Qs·ps Pl-power lost-causes heating of the working fluid Pl=Pl1+Pl2 Pl1-power lost through throttle valve: Pl1=Qs(pmax-ps) Pl2-power lost through safety valve: Pl2=(Qmax-Qs)pmax Significant power loss when pressure and flow required by pump are low.

Reducing energy losses by using “LS” pumps Constant Flow and Load Sensing Pump Qs-load flow; Qmax-pump flow; ps-load pressure; p-pressure drop in the throttle valve Pu-power used- generates mechanical work: Pu=Qs·ps Pl-power lost- causes heating of the working fluid Pl=Pl1+Pl2 Pl1-power lost through throttle valve: Pl1=Qs·p Pl2-power lost through flow control valve: Pl2=(Qmax-Q)(ps+p) Good power balance. Load flow is constant regardless of load pressure variations.

Reducing energy losses by using “LS” pumps Variable Flow and Load Sensing Pump Qs-load flow; ps-load pressure; p-pressure drop in the throttle valve Pu-power used- generates mechanical work: Pu=Qs·ps Pl-power lost- causes heating of the working fluid: Pl=Qs·p Very good power balance. Load flow is constant regardless of load pressure variations and/or drive speed variation (heat engine).

Digital pumping systems Increasing efficiency of Fluid Power systems by means of digital hydraulics Digital pumping systems Digital pumping system in parallel connection b) Digital pumps with each piston controlled For instance: √ three non-adjustable pumps driven by a single shaft √ directional control valves in parallel controlled by a binary algorithm For instance: √ pump with three pistons arranged in line √ each piston may pump into the system or may run idle Advantages of digital pumps: - They can be built out of simple parts; - They have fast operation; - They can drive several actuation parts (joint/shared use); - Energy savings, especially during joint use and under partial load.

Kinetic and/or potential energy recovery and reuse Kinetic energy recovery Conceptual model of a kinetic energy recovery system The hydraulic recovery system is conceived like a mechatronics system, usable for medium and heavy motor vehicles. Implementation of the kinetic energy recovery hydraulic system on a motor vehicle transforms it into a hybrid vehicle and leads to decreasing the fuel consumption and reducing the gas emissions. In this manner, the negative impact on the environment and on the fossil energy resources will be reduced.

Kinetic and/or potential energy recovery and reuse → Fuel reduction and CO2 savings → Operator does not feel any differences → About 54 % of the potential energy can be regenerated

PhD.Eng. Ioan LEPĂDATU lepadatu.ihp@fluidas.ro Thank you! CONTACT PERSON: PhD.Eng. Ioan LEPĂDATU lepadatu.ihp@fluidas.ro