Degradation of Hydraulic Oil in Operating Conditions

This paper addresses the study of hydraulic oil degradation, the increase in the number of wear metals, and contaminants in the monitored oil sample during 6 months of operation of an agricultural tractor. In a closed hydraulic circuit, the oil undergoes gradual degradation due to operational influences, which is caused not only by contamination from external impurities but also by the mixing of operational fluids from other attachment devices. Chemical analysis, water content measurements, and ferography were conducted on a sample of HARVELLA TX 10W40 hydraulic oil, which was compared with a sample of new, uncontaminated oil. The condition of operational fluids affects the proper functioning and lifespan of hydraulic circuit components and is one of the diagnostic indicators of their wear. During the operation of the equipment, the mixing of hydraulic oil from the main device and attachment devices occurs, resulting in changes to the operational properties of the fluid. The study compared the state and contamination of the mixed fluid in the tractor's internal hydraulic circuit with the hydraulic fluid applied by the manufacturer in new equipment. The measurement results indicated that during the experiment, no significant contamination of the oil occurred from pollutant elements present in the external environment, and the physicochemical properties of the monitored fluid were not significantly reduced.