Weiss Mobiltechnik GmbH ELectro-hydrauLic demand flow controL Energy-efficient, responsive, forward-looking

Development goals The development of eBSS was carried out in cooperation with the Chair of Mobile Machinery. The general idea behind the project was to optimise the working hydraulics of mobile machines, especially to increase of efficiency of a forestry crane hydraulic system. By minimising principle-related losses of a load-sensing control, the goal was to save energy by more than 10% by using an electro-hydraulic demand flow control (eBSS). The following objectives were defined: • Reduction in fuel consumption • Minimisation of cooling power requirement • Reduced oil temperature » lifetime...

WMTpart eBSS Implementation Hydraulic-mechanical load sensing Electro-hydraulic demand flow control

Comparison LS - eBSS WMT part eBSS The electro-hydraulic demand flow control (eBSS) is an innovative system to control pumps and valves in an open circuit. The system is suitable for stationary and mobile applications. The pump is controlled electronically and adjusted to the volumetric flow rate requirements of the valves. This results in very direct control of the consumers and the energy consumption of the load sensing systems can be reduced noticeably. By controlling the pump without feedback, vibrations can be avoided and the reaction time is noticeably shorter compared to LS systems. For...

• 2 x M4-15 control block for crane • 1 x M4-12 control block for additional functions • 2 x LVS12 control block with digital pilot head for crane • 1 x M4-12 control block for additional functions Weifi Holzentrindung GmbH Debarking machine

WMTpart eBSS Load cycle

WMTpart eBSS Simulation results for energy requirement Suitable for all open hydraulic circuits in mobile and stationary applications Fast and vibration-free control Energy savings of 10 - 20 % compared to load sensing systems (LS) Very good cold start behaviour Realisable with standard com

Modes of operationeBSS Pump volumetric flow rate is adjusted electro-hydraulically to the consumers Electric load-sensing (differential pressure control) Standard functions Additional functions Valves • Volumetric flow rate limitation OEM and operator • Control curve Valves • Load-dependent volumetric flow rate reduction • Load control • Priority function Pump • Volumetric flow rate calculation and swivel angle control • Volumetric flow rate limitation • Safety cut-out Pump • Temperature-dependent volumetric flow rate limitation • Load control for individual pump and combination

Sections with separate control edge Operating modes Description eBSS can also be used with separate control edges. Four different operating modes are supported. Use of separate control edges increases energy efficiency compared to conventional valves and improves the controllability of the machine at high loads. The exit side is adjusted to the load and the resolution at the joystick is not reduced as a result. The crane can be controlled load-independently as a result. NOM - Normal operating mode RgOM - Regenerative mode EOM - Energy-neutral mode RcOM - Recuperation mode

Circuit design of separate control edges Advantage • Individual control of the exit side • Fast response • Good load control

Fully configurable and ready-to-in-stall complete systems Hardware based solutions, preconfigured and tested Flexible solutions on-site and remote Interfaces for external systems - remote and local Weiss Mobiltechnik GmbH Weiss Mobiltechnik GmbH © 2019 All Rights Reserved