EXAMINATION OF SELECTED GEOMETRICAL PARAMETERS OF WHEELSETS OF ELECTRIC MULTIPLE UNIT

Abstract

The aim of the work is to investigate changes in the values of selected geometrical parameters of electric multiple unit (EMU) wheelsets as a function of mileage. Based on the conducted analysis of the literature, it was found that the problem of proper diagnostics and maintenance of wheelsets, as an element that directly affects the level of safety of railway vehicle traffic, is very up-to-date and justified. This work presents the characteristics of the geometrical parameters of the wheelset that were subjected to the tests. According to the terminology of EN 13715:2020-12, the geometrical parameters of the wheelset subjected to tests were characterized. As part of the research work, data from measurements of the values of the main geometrical parameters of the outer contour of the wheelsets were collected and systematized from 204 measurement sheets of vehicles. Data were collected from specially developed registers and databases. The research and analyses confirm the existence of a correlation between changes in the values of diagnostic characteristics of flange thickness and height and flange steepness as a function of kilometrage. The intensity of wheel rim wear changes depending on the conditions under which the vehicle is operated. The wheelsets’ diagnostic characteristics were not fully predictable, which makes it difficult to forecast their future values. Based on the obtained results, actions that increase the durability of the wheels were proposed. For example, it is reasonable to assign vehicles to different routes so that the wheel rims wear evenly, eliminating the need for the subsequent accumulation of repairs and wheelset replacements before repair at the P4 level. Moreover, it is advisable to undertake work on the change of identification of basic individual primary characteristics of the wheel’s external contour into primary characteristics of a collective nature. As a result of such action, it is possible to indicate the probability of occurrence of non-uniformity of values of diagnostic characteristics on the wheel circumference could be limited and the phenomenon of occurrence of measurement errors could be minimized.