DETERMINATION OF THE FREQUENCY OF NATURAL OSCILLATIONS OF THE ELEMENTS OF THE MECHANICAL SYSTEM OF THE MOTOR CARRIAGE ROLLING STOCK

Abstract

The article is devoted to highlighting the peculiarities of determining the frequencies of natural oscillations of the elements of the mechanical system of modern rolling stock. A significant volume of passenger transportation in suburban traffic on railway networks of Ukraine is carried out by the operating fleet of rolling stock, most of which are operated overtime. Taking into account the relatively slow pace of renewal of Ukrzaliznytsia's rolling stock fleet, scientific research aimed at maintaining a high level of technical and economic indicators of electric trains in operation becomes especially important. Therefore, research aimed at improving performance indicators of structural elements of rolling stock should be considered relevant. As one of the most responsible units of the mechanical system of modern rolling stock, the crew part can be singled out, which includes a traction electric drive, during the operation of which the phenomenon of jolts is observed in some modes of operation. Such a phenomenon is observed in resonant modes of operation, that is, the coincidence of the frequencies of natural and forced oscillations, which negatively affects the reliability and durability of the mechanical system as a whole. Therefore, the task of identifying resonant frequencies and eliminating the manifestation of the negative phenomenon of resonance arises. One of the possible ways to solve the given problem is to adjust the operation of the traction drive mechanism in non-resonant modes, which in turn requires research on the torsional oscillations of the mechanical drive system. The article presents an approach using geometric models of the design elements of the traction drive of electric trains, the corresponding mathematical model, and the results of modeling the shape of the frequency of natural oscillations of the traction drive of an electric train. Based on the results of the calculations, it was determined that the form of natural oscillation frequencies of the considered mechanical system has a two-node character. The proposed approach is based on the use of a tabular form of calculation of recurrent formulas. Based on the results of the research, recommendations are given for the further use of the obtained results. Keywords: motor-wagon rolling stock, electric train, traction drive, self-oscillations.