STREAMLINING THE ACTUATION OF HEAVY AND HIGH-MAGNITUDE DYNAMIC LOAD HYDRAULIC CYLINDERS IN THE FIELD OF EXPLORATION AND MINING

Abstract

In the exploration and mining industry, fixed and mobile machines use hydraulic drive systems (HDSs) involving hydraulic cylinders powered at high pressure rates. Such cylinders operate in heavy and high-magnitude dynamic load regimes, e.g., as part of mobile crusher buckets, excavators and mini excavators, hook-lift trailers, or mobile hydraulic jacks. In this context, there are two solutions for generating high pressure rates in HDSs: (1) by using high-pressure pumps, or (2) by using hydraulic power units consisting of low-pressure pumping units and oscillating hydraulic pressure intensifiers. The second solution is often used in static applications, such as burst tests of pipes and tanks, and dynamic applications involving short displacements of hydraulic cylinders, such as in hydraulic tools and presses. This solution proves to be more efficient in terms of energy and economically. To assess the efficiency of this type of hydraulic drive in the field of exploration and mining, the authors developed a test stand. The stand made it possible for the highpressure hydraulic cylinder to be loaded with heavy and high-magnitude dynamic loads, using a step ramp-like configuration with different slopes for the two displacement directions. Next, the cylinder was supplied from a low-pressure pumping unit equipped with a minibooster, and tested under these load conditions. Test results pointed out that the tested hydraulic cylinder moves continuously and safely over the entire forwardand- return stroke. Low-pressure pumping units equipped with miniboosters are an efficient solution for driving hydraulic cylinders in the field of exploration and mining, especially in the case of heavy and high-magnitude dynamic loads.