Excavator with two or three arms: Dynamical behavior and structural implications

Abstract

The purpose of this work is to compare, with the same digging diagrams, the velocity, accelerations and dynamic performances of two excavators with different arm configurations. In particular, constructive solutions involving the use of two and three mobile arms will be examined. For excavators the different construction geometry (2-3 arms) is mainly dictated by reasons of use, in fact the 3 arms solution is normally used in areas that allow poor mobility of vehicle and present obstacles during the excavation phase. The dynamic comparison between the two solutions is performed on real working conditions to which they can be subjected during the exercise. The elaborations are performed both analytically and numerically. Essentially the analysis shows that in the condition of leveling and lifting at minimum distance from the rotation axis the dynamic performances are similar, there are significant differences in the lifting condition at the maximum distance. The diversity also implies significant variations in the forces of the hydraulic cylinders used to move both the load and the arms, an aspect which finds greater emphasis even in the case in which the arms are made by adopting unconventional materials for their realization as aluminum and composites.

An Assessment of Low-Cost Tractor Motorization with Main Farming Implements

“…Caterpillar also developed a hybrid bulldozer (D7E Hybrid) and increased fuel efficiency by 20 percent compared with its predecessor [16]. In contrast to the automotive industry, the construction machinery industry has applied hybrid technologies to workpieces such as boom and bucket systems, and most studies have focused on using excavators [17].…”