Marginal Column

Illustration | Bosch Rexroth AG

Reduction: Optimizing mobile working machines


Taking a view of the entire system, Rexroth solutions help make diggers, loaders, tracked vehicles and the like cleaner and more efficient. In order to comply with the limit values set down in the TIER 4 Final exhaust quality standard, which becomes effective as of 2014, it will be necessary – in addition to the mandated exhaust gas treatment system in these off-road vehicles – not only to optimize the diesel engine. The entire system will have to be redesigned, including engine management, auxiliary components, working hydraulics and the propulsion system. To increase the overall efficiency of mobile working machines it might make sense to introduce intense and direct communications between the hydraulic control devices and the diesel controls.

An initial and very promising concept for this purpose is diesel hydraulic control (DHC). Intelligent energy management can also make a contribution to significantly increased efficiency. Vehicles whose propulsion systems and working hydraulics are subjected to extreme starts and stops can reduce energy consumption with hybrid hydraulic solutions. Concepts such as the hydrostatic regenerative braking system (HRB) even today make decisive contributions to improving overall system efficiency.

With the hydraulic flywheel (HFW), Rexroth has developed a new concept for hydrostatic drives that accommodates the changes in the operating characteristics of the latest generation of engines. Due to the TIER 4 final requirements, tomorrow’s engines will be more sluggish as they respond to load application. One of the potential use strategies for the HFW will compensate for this by boosting energy to the hydrostatic propulsion drive or the working hydraulics. This makes the HFW a genuine BlueHydraulics solution for mobile working machines. Rexroth uses the term BlueHydraulics to designate solutions in mobile hydraulic concepts that – in a very special way – save energy, boost efficiency and reduce emissions.