Equipment for bearing housing change of work rolls in a steckel mill

Sammanfattning: Outokumpu Stainless AB operates in the production and development of stainless steels. In their hot rolling mill in Avesta there is a need to introduce an equipment to shift bearing housings on the steckel mill work rolls. Today this is accomplished manually with an overhead crane, jack, sledgehammer and pry-bar. It causes strain on the operators and the equipment may be damaged in the process.On behalf of Outokumpu Stainless AB, Bilfinger started this project as a thesis with the objective to develop a design proposal for a machine that meets the requirements for an easier and better handling of the bearing housing changes. In this thesis the author presents some concepts on how the machine could work, analysis of forces which occur when the roll assembly is placed on the table, a simple model to estimate the needed force to remove the bearing housing from the work roll as well as force and FEM analysis of the machine. The result was a machine consisting of a table to place the roll upon and two pullers, one for each bearing housing, which brings the bearing housing with it when actuated by a hydraulic cylinder. The machine meets all of the set requirements except for the production cost and the power of the hydraulic cylinder while retracting (30% lower). A rough estimation of the production and installation cost is estimated at just over 1 MSEK.