Implementing approach of rolling process for inner spline sleeve with medium diameter: radial-feed rolling and through-feed rolling

Spline connection is a key component for force- and torque-transmission, which is widely used in mechanical engineering. External splines in spline connection have been manufactured by rolling process, but the matched inner splines manufactured by plastic deformation are few. Especially, the long inner spline is usually manufactured by cutting process. The rolling process is a plastic forming process with local loading and force saving; so, this study investigated the rolling process and its implementing way for inner spline sleeve. A radial-feed rolling process and two through-feed rolling processes with different structure of entry-angle section were proposed, and the finite element (FE) models were established for different rolling process, respectively. For the FE model of the through-feed rolling process, a multiple meshing strategy is used such as the local refinement window moving along axial direction with rolling die and the total number of mesh increasing by stages. The results indicated that the contact area is the same along axial direction and increases in situ during radial-feed rolling process, but the contact area changes and moves along axial direction during through-feed rolling process; the full and clear shape of inner spline can be obtained by the three rolling processes, but the shapes near the end of expected zone with inner spline are different for the different processes, and the geometry near the end of billet and the rolling process have the influence on the shapes near the end; some metal is accumulated in front of the through-feed rolling die, so non-full teeth present in the entered end by the rolling die and full teeth in the exited end will be out of the expected zone with inner spline.