The influence of hollow billet thickness in rotary compression

The study presents a selection of numerical and experimental results of producing hollow stepped shafts. The first part of this study describes the advantages of using hollow parts in machine design and discusses the main fields of their applications. Next, an innovative rotary compression method for producing stepped axes and shafts is proposed. In order to estimate the technological potential of rotary compression, we performed comprehensive numerical and experimental analyses of producing hollow stepped shafts by this new technique. First, the rotary compression process for hollow parts was modeled numerically by the finite element method. The 3D modeling was made using the Simufact Forming software. The numerical results were then verified by experimental tests conducted under laboratory conditions. The experiments were performed using a machine designed by the authors of the present study. The following variables were investigated in the experiments: the effect of billet wall thickness on the process, the quality and geometry of products, and variations in loads and torques. The experimental results confirm that rotary compression can be used to produce hollow stepped shafts with a wide range of thicknesses.