Browsing by Author "Skvireckas, R."
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Item Consideration of Dependent Failures Impact on Selecting the System of Locomotive Maintenance(Kaunas Univ. of Technology, Palanga, Lithuania, 2019) Bodnar, Borys Ye.; Ochkasov, Oleksandr B.; Bodnar, Yevhen B.; Hryshechkina, Tatiana S.; Skvireckas, R.ENG: Modern measures aimed at reducing the operating costs are closely related to such concepts as LCC and RAMS-approach. The article analyzes the existing standards that regulate their usage. The purpose of the research is to improve the methodology for determining the renewal costs of locomotive nodes with due regard to dependent failures. To describe the propagation of dependent failures in the system, the authors propose to use the wave approach. The dependent failures impact on the system is determined on the basis of information about the relationship between elements and data from a technological-economic map concerning the cost of locomotive nodes renewal. To take into account the probabilistic nature, the authors propose to use the methods of expert research for determining the probability of failure of dependent elements. The authors proposed a method for determining the probability of the locomotive nodes breakdown considering the dependent failures. The method of calculating the average cost of unscheduled repair, considering the dependent failures of interrelated elements was improved. For the first time, a recurrence relation on a set is deduced, by which the volume of damage is calculated at the dependent failures of elements in a complex system. The coefficient, which will allow assessing the impact of dependent failures on the maintenance system and the life cycle cost of a locomotive, is proposed. On the basis of the proposed method, the calculations for the electric equipment of electric locomotives, DE1 series were made. A comparison of the renewal cost of electrical equipment with considering the dependent failures of related elements was made.Item The Impact of Motor Oils Quality on Improving the Reliability in Operation of Traction Rolling Stock(Kaunas Univ. of Technology, Lithuania, 2020) Zelenko, Yuliia V.; Bezovska, Maryna S.; Skvireckas, R.; Neduzha, Larysa O.EN: In modern operating conditions of rolling stock, railway safety is one of the priority issues. The safe operation of traction rolling stock is impossible without the effective use of all its components. One of the main characteristics of rolling stock is the reliability, the level of which is associated with the efficiency of its operation. The reliability is closely related to such an important issue as the environmental safety in operating of a railway vehicle. Domestic and world experience in operating autonomous locomotives indicates that diesel power plants play a decisive role in this. An important part of diesel engine in a locomotive is the oil system. The annual formation of a significant amount of used oils requires solving the problem of their further safe storage. The article considers the impact of motor oils quality on the reliability in operation of traction rolling stock. In this connection, a new method in recovering of used oils of different marks and returning them to the production process is proposed. This will contribute to increasing the safety in operation of railway equipment on the railways, improved economic performance, minimizing the amount of waste and their negative effect on the environment and so on.Item Use of the Wavelet Transform for the Analysis of Irregularity of Crankshaft Angular Velocity(Kaunas University of Technology; Publishing House “Technologija“, Kaunas, Lithuania, 2018) Bodnar, Borys Ye.; Ochkasov, Oleksandr B.; Chernyayev, Dmytro V.; Skvireckas, R.ENG: The issue of quick and qualitative receiving of reliable and complete information concerning the technical state of a diesel engine in the locomotive is relevant one, although there are already many technical solutions in this direction. Indirect methods for diesel engine diagnostics are of gain ground. Among the existing methods, the diagnostics of the diesel engine technical state occupies a special place due to the analysis of irregularity of crankshaft angular velocity. Within the working cycle of the diesel engine, the crankshaft angular velocity of rotation is constantly changed. The mechanical inertia system of the pistons, rods and shaft receives impulses of mechanical energy from fuel combustion, as well as pulsed losses of kinetic energy on pump pistons-stroke. Thus, the value and shape of the torque of each cylinder affects the angular velocity of the shaft. The purpose of the research is to study the various types’ application for basic functions of wavelet transform to emphasize the diagnostic information from the signal of angular velocity irregularity of the diesel engine shaft. This will automate the process of diagnosing the diesel engine. The authors conducted simulation of the working process of a shunting diesel locomotive with hydrodynamic transmission. Type of the diesel engine: six-cylinder in-line engine with turbo-charger, power 750 hp. The nominal modes of the diesel engine operation at the crankshaft speed of 1400 rpm were considered. There are simulation of the fault-free condition and two types of faults: the change of fuel injection advance angle and change of the cycle fuel injection to greater and smaller sides from the passport date. For the resulting angular-velocity vectors and acceleration we applied continuous wavelet transform with different basic functions. The obtained results are estimated by energy criteria. The most promising basic functions are separated from the point of view of the most complete estimation of the energy for the portion of the signal carrying diagnostic information.