Methods for increasing the fatigue life, of crankshafts
AssigneeMaschinenfabrik Alfing Kessler GmbH
InventorsAlfons Reeb, Jochen Schmidt, Alexis Boemcke
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Abstract
The invention relates to a method for increasing the bending strength and the endurance limit of crankshafts by locally restricted hammering in areas of high stress, such as grooves, the mouths of bores and cross-sectional transition zones, in which method pressure impulse machines or beating devices comprising heating tools are employed. The pressure impulse machines or beating devices only execute a relative displacement of the beating tool against the surface of the crankshaft segment to be processed when the compressive stress is introduced between the heating tool and said surface of the crankshaft segment to be processed. The invention also relates to a device for increasing the endurance limit of crankshafts.
Claims19
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.
Dependencies are inferred from the claim text.