Rolling Processing And Strength Analysis Of Crankshaft Fillet Strengthen For Air Compressor

Crankshaft is one of the key component of piston-type air compressor. Thesealternating loads act on the entire crankshaft make it generate bending, torsion andcomplex alternating stresses, result in fatigue crack, especially at the transition fillet of thecrankshaft main journals and the rod diameter. To study the key technologies oncrankshaft fillet rolling and develop the related equipment have greatly significance inpractical applications. This article has done the following works on rolling process andfatigue strength of crankshaft fillet strengthen for air compressor.(1) For the force and fatigue damage of air compressor crankshaft, the crankshaftfillet rolling residual stress mechanism and the under cutting rolling strengtheningtechnology are analyzed. The undercut fillet rolling method is selected as the numericalexperiments of crankshaft fillet rolling strengthening process for air compressor.(2) By analyzing the deformation and stress distribution on the rolling contact withthe arc, the scope of fillet rolling loads is determined. A numerical simulation of therolling process for crankshaft rolling model was conducted in DEFORM software. It canbe got the results that the rolling effect of crankshaft fillet deformation and residual stressis not ideal when rolling speed is30r/min,40r/min. But the rolling process is stable andthe residual stress results are more accurate when rolling speed is50r/min.(3) The kinematics analysis was conducted by ADAMS software through processsimulation of crankshaft connecting rod system in air compressor. The kineticcharacteristic of each part and forces exerted on crankshaft journal and crankpin areobtained. In view of the stress concentration situation between main journal and thetransition of connecting rod journal fillet under the circumstance of load. Through thecrank pin in dynamic force and the numerical simulation of the residual stress, strength ofcrankshaft is finished by NX-NASTRAN software. It can be found that the journal filletarea of stress concentration is decreased obviously through comparison before and afterthe fillet rolling. The effectiveness of the rolling process is verified. And the bestcombination of rolling process parameters has been determined.