A Railway Wheelset Optimally Designed for Cold Press Fitting

Abstract

In the present paper, the press fitting of railway wheels is studied with the aim of defining the mechanical and physical parameters to be adopted in order to reduce as much as possible the damaging of both wheel and axle during repeated press fitting and wheel removals. The study has been performed in a theoretical way, through a new multi objective optimisation method based on finite elements analyses. The FEM model has been experimentally validated. Referring to an actual case, the parameters that influences the press fitting process have been determined. The parameters influence was related not only to the mechanical stresses into the structures of wheel and axle respectively, but also to the robustness of the design (sensitivity to the machining tolerances and to friction coefficient variation at the press fit surfaces). Some optimal solutions have been determined and compared (in terms of performances) with an actual production one.