This paper investigates the energy efficiency of an articulated steering system in a wheel loader, focusing on a comparative study between conventional Orbital Steering Unit (OSP) and a proposed Electro-Hydrostatic Steering (EHS) system. The conventional OSP on a large wheel loader serves as the benchmark for evaluating the hydraulic power consumption during different steering manoeuvres. For the conventional steering the power delivered by the load-sensing hydrostatic pump is calculated from the experimental data and losses in the OSP unit are calculated. Whereas, for the EHS the mechanical power needed to operate the fixed displacement pump is considered as input and losses are calculated for performing the same steering profile while delivering similar dynamic steering performance, using the simulation model. It has been found that in the OSP steering system the efficiency remained at around 40%, whereas in the EHS system it ranges from 69.4% to 81.3%.
Singh et al. (2026) studied this question.