A process for roll straightening of crankshafts has been detailed in DE 30 37 688 C2. In accordance with this process, a crankshaft from a series that is in line for rolling is deep rolled with a constant force of F0, which corresponds to approx ⅓ of the minimum deep rolling force required to attain the desired fatigue strength. Once this is complete, the crankshaft is removed and the curve and size of the angle widening that has occurred are measured. Roll straightening is then performed using the appropriate machine setting at a force of F1, the curve of which across the crankshaft's angle of rotation is approximately proportional to the ratio of the largest angle widening to the local angle widening. As such, in accordance with the established process, the runout of the crankshaft, which it receives as a result of the deep rolling, is measured against the angle widenings of the crank arm. This type of measurement is complicated and imprecise. Furthermore, with the established process it is only ever possible to straighten a certain series, i.e. a pre-defined number of crankshafts of the same type. To this end, “roll straightening tables” have been drawn up in order to ensure that each crankshaft in the series lined up for rolling is always roll straightened according to the same pattern. This requires a high consistency of production for the crankshafts that are to be deep rolled. Deviations in individual crankshafts cannot be taken into account with this model. Furthermore, as stated above, the deep rolling force constantly fluctuates over the curve of the circumference of the bearing pin that is line up for rolling. The constant fluctuation between minimum and maximum deep rolling force protects the machine and tools.
Furthermore, allowing oscillation of the deep rolling force is established in DE 29 20 889 C2.