Re-design of tyred wheels to optimize maintenance

Resources needed to maintain conventional tyred wheels are much bigger than those required by monobloc wheels. A different geometry of the mating surfaces, basically a self-centring dovetail coupling, is proposed. It allows to eliminate the retaining ring resulting in an increase safety. This change is justified by the widespread diffusion of CNC machine tools and Coordinate Measuring Machines (CMM). The adoption of this safer modified geometry leads to a simplified maintenance cycle that is much faster and much cheaper than the conventional one. Historical maintenance procedures are revised in the paper, showing how the new maintenance cycle is easy, and has a low impact on current maintenance plants. The overhaul process looks particularly advantageous on inboard bearings wheelsets installed on inside frame bogies, for which it appears that tyre change can be performed directly on the vehicle during a sort of “pit stop”.