Non-circular Grinding of Backup Rolls to Reduce Rolling Force Variation

A common structure in hot strip mill backup roll bearings is to attach the conical sleeve of the slide bearing to the roll's shaft by a key. The key groove, cut to the conical sleeve, locally causes deformation under load. This sleeve spring is observed as rolling force variation. A new method to minimize force variations, based on 3D grinding of the backup rolls, was developed. A non-circular shape was ground on the rolls. The empirical research took place at a hot strip mill. As a result, the 3D ground non-circular geometry of the backup rolls considerably reduced the rolling force variation.