A method of fretting wear reduction in an automatic wheel set gauge change system

• The SUW 2000 enables a fluent gauge change of the tracks 1435/1520 mm.
• The SUW 2000 system allows its mounting in all railway freight carriages.
• It is appropriate to look for new technologies which can limit fretting wear.
• The application of molybdenum coating efficiently limits fretting wear occurrence.
• A distinct influence of lubricants on fretting wear limitation was noticed.

The SUW 2000 railway vehicle wheel set with an automatic gauge change system is especially exposed to fatigue wear due to the specific working conditions. Taking into consideration the role which a wheel set has in both vehicle handling on a track and providing safety of railway traffic, the wheel set damage is impermissible. It also applies to the sleeve–axle rotational connection. This article presents research into both finding new and low-cost materials for a slide sleeve in the wheel hub node and looking for cheaper technologies for improving the surface layer of the wheel set under-hub which would eliminate fretting wear. The research was conducted on a simplified physical model of a real connection between a wheel and an axle. The results of the conducted wear tests show that fretting wear can be effectively limited by applying a metallic layer in the form of molybdenum coating. Grease with the addition of molybdenum disulphide can also protect the co-operating surfaces against fretting wear. It also allows for sustaining proper working conditions of frictional pair elements. This solution, however, is onerous due to the limited maintainability of the connection node. The studies carried out show that there is a full possibility of using this solution in real exploitation.