Hydraulic travel drives

Research Task/Objectives

In many mobile machines, the travel drive is responsible for important working functions and significantly influences the machine’s performance. Driven by increasing energy costs, legal  requirements and competition, many research and development activities focus on the improvement of energy efficiency. The assessment of different solutions is a mayor challenge for both the machine and the transmission  manufacturers. The physical relationships are complex, the number of possible variants is vast. Experiment-based evaluation of different transmission solutions is not  practicable due to the immense design effort. Objective of the research activities is the simulation-based analysis and enhancement of travel drive solutions.

Approach/Results

The simulation-based analysis requires detailed parameterisable and connectable models of all components relevant for the drive system’s performance and  functionality. Apart from the diesel engine, these are for example planetary gear sets, bearings, clutches and hydraulic displacement units and their control devices.
The specific design and the impartial comparison of different system solutions requires a
consideration of the machine and applicationspecific load scenario. Based on that, the individual potential of different system solutions can be   demonstrated. Particular attention is payed to the transmission’s structure,  dimensioning and control as well as to the interaction between diesel engine and travel drive transmission.

This research is based on the project "Analysis and improvement of drive train concepts for mobile machines" initiated and financed by the Forschungsfonds Fluidtechnik within VDMA (FKM Nr. 071340).