Sławomir Kowalski
Technical Transactions, Mechanics Issue 1-M (4) 2014, 2014, pp. 49-62
https://doi.org/10.4467/2353737XCT.14.048.2498This article presents brief characteristics of rail vehicles modernised or produced by NEWAG S.A. The article discusses currently produced and modernised Electric Multiple Units (EMUs) and Diesel Multiple Units (DMUs) as well as diesel locomotives undergoing a modernisation process. Based on the presented characteristics, the rail vehicle modernisation and construction process trends prevailing in the contemporary railway market were brought closer to the reader.
Sławomir Kowalski
Technical Transactions, Volume 4 Year 2018 (115), 2018, pp. 173-187
https://doi.org/10.4467/2353737XCT.18.065.8377The tests were conducted on a wheel/axle press-fit joint model, which consisted of a shaft and a sleeve. Macrographic observations were demonstrated fretting wear on the shaft surface with and without coatings. In the case of the uncoated shaft, wear around the entire circumference of the axle seat was visible in the form of a peculiar ring of a specific width. The coated shaft surface was distinguished by a considerably smaller number of visible traces of wear. Wear was observed around the entire circumference of the axle seat, was spaced at random, and insignificantly sized areas each time. Micrographic observations with the use of a scanning microscope demonstrated that fretting was primarily comprised of the build-up of the material from both surfaces joined together. In addition to the build-up, surface micro-abrasion, micropits and microcracks are observed, albeit to a lesser extent.