IMPROVEMENT OF QUALITY AND OPERATIONAL PROPERTIES OF CRANKSHAFTS BY VIBRATION-IMPACT METHOD

In the paper, to improve the quality and operational properties of internal combustion engine crankshafts, a method of hardening by surface plastic deformation by means of shock-vibrating machining (ShBM) with steel balls is proposed. The manufacturing scheme to implement the method is developed. Experimental studies are conducted showing the effectiveness of its use to improve the quality and structural strength of crankshafts. The reduction of surface roughness to Ra=0.08 microns in fillets and the complete disappearance of residual ridges after grinding and polishing shafts as geometric stress concentrators and places of fatigue microcracks have a significant effect on increasing the fatigue strength of crankshafts. It is found out that the stabilizing effect accompanying hardening by this method is one of the main factors ensuring a reduction in crankshaft distortion and an increase in their fatigue strength.