Research and modeling of wear of driving and rolling wheel sets in the ELF I electric multiple unit

The aim of the article is to present the results of research and modelling of wheel set wear on the rolling diameter of the drive and rolling wheels of a multi-unit traction unit. The object of the research was the PESA ELF I electric multiple unit constructed as a five-unit unit based on two end drive bogies and three central rolling bogies. The article presents the results of research on the change in wheel diameter recorded every two months during a periodic inspection over a period of five years of vehicle operation until revision repair. Based on the results of wheel diameter tests, wear was determined, on the basis of which the change in wheel diameter and wear as a function of time and vehicle mileage was modelled. Based on the models, mileages expressed in kilometres were determined for each wheel set with longer vehicle operation. The reason for implementing the subject is the uneven wear of individual wheels in the wheel set of drive and rolling bogies in multi-unit traction units. The vehicle maintenance system documentation requires that after a specified period of time, e.g. 5 years, the vehicle is sent for a revision repair, even if none of the wheel sets has reached the wear limit.