Patent ID: 8011096

Claim:
A method for increasing the fatigue life, in particular the bending fatigue life and the torsional fatigue life of crankshafts, in particular of large crankshafts, by local hammering of highly loaded areas, such as grooves, hole mouths and cross-sectional junctions, by means of pulsed-pressure machines or striking apparatuses which introduce intrinsic compressive stresses into the crankshaft via striking tools, characterized in that the pulsed-pressure apparatuses or striking machines carry out only a relative movement on a plane at right angles to the surface of the crankshaft segment at the time at which the compressive stress is introduced between the striking tool and the crankshaft segment to be processed, with the crankshaft being rotated continuously during the processing, and in that the time during which the striking tool is acting and the striking pressures are chosen such that, when the striking tool strikes the crankshaft segment to be processed while the intrinsic compressive stresses are being introduced, the rotational movement of the crankshaft is necessarily stopped.