Determining the Influence of Carbon Black in Oil on the Wear Resistance of Elements in the Tribological System "Steel – Oil – Bronze"

The results of experimental research into the influence of the concentration of carbon black in industrial oil I-30А and on wear resistance of the tribological system "steel-oil-bronze" are presented. It is assumed that carbon black, obtained by the electric arc method under laboratory conditions, consists of conglomerates and micro-and nanoparticles of carbon, which are found in a wide range from nanometers to tenths of millimeters.The procedure, materials, and equipment for experimental studies of wear resistance of the parts of the tribosystem "steel-bronze" on the friction machine SMC-2 was shown. The research procedure methodology involved the variation by two independent factors: concentration of carbon black in industrial oil I-30А and external loading. Sliding velocity, contour area of the contact and initial temperature of the tribosystem remained constant factors.The obtained experimental data made it possible to establish two main patterns that characterize the process of friction and wear in the studied tribological system. The first pattern reveals the influence of the concentration of carbon black in industrial oil I-30А and external load on friction torque in the couple "steel‒bronze". The second pattern reveals the influence of the same factors on wear resistance of the parts that were tested on the friction machine. The obtained patterns correlate among themselves and determine the scope of rational concentration of conglomerates of micro- and nanoparticles of carbon in industrial oil I-30A, which was applied as a lubricant in the tested tribological system.At the final stage of the research, the surfaces of the parts of friction were studied at the atomic-force microscope "Solver P47-Pro" made by manufacturing company NT-MDT. These studies made it possible to reveal the mechanism of modification of the surface layer of steel and bronze by carbon nanoparticles in their interaction in the tribological system at friction

Development of the Universal Model of Mechatronic System with a Hydraulic Drive

The growing demands to performance of mechatronic systems with a hydraulic drive of movable operating elements of self-propelled machines require application of new approaches to the process of their development and design. Functional parameters of the mechatronic systems depend on a rational choice of operating modes of the hydraulic system and the design implementation of the mechatronic modules of these systems. Quality of the mechanically driven mechatronic system is largely determined by its dynamic characteristics. In order to improve dynamic characteristics, a universal model describing dynamic and static processes occurring in the elements of the mechatronic system was proposed. The pump, the hydraulic motor, the safety valve and the working fluid are considered interrelated as a single whole. The universal model takes into account peculiarities of functioning and mutual influence of all elements of the mechatronic system as well as the features of the working fluid and can be used with any hydraulic machines of a volumetric action. The study of dynamics of the changes in functional parameters of the mechanically driven mechatronic system was carried out for four stages of its operation: acceleration of the hydraulic drive (triggering of the safety valve); valve closure; completion of acceleration and steady-state operation. The conducted studies have established that when activating the hydraulic drive of the mechatronic system from the moment of the safety valve activation and to its closure, operating conditions do not affect changes in the functional parameters. In the steady-state operation, there are fluctuations caused by unevenness of the pump feed and load fluctuations. It should also be noted that the mechatronic system with a hydraulic motor having larger working volume has better dynamic characteristics than that with smaller working volume