Key Technology Research And Optimization Of Marine Medium Speed Diesel Engine Crankshaft

Diesel engine is the heart of the marine,its quality affects the efficient operation of the marine.Therefore,all around the world,diesel engine manufacturers focus on the process of crankshaft,because crankshaft is one of the key parts.In order to improve machining accuracy,efficiency and reduce cost,we have researched and optimized the machining process of A23 H crankshaft,the main achievements are as follows:1.Crank throw is taken as the research object,which is the off-centre part of crankshaft,including crank pin journal,crank pin journal arc and crank arm.Instead of traditional processing equipments and cutting tools,an advanced five axis machining center,which has the functions of turning and milling,is introduced to research and optimize the processing of the crank throw.2.Crankshaft journal is taken as the research object,we have studied the fine grinding and polishing processes.Firstly,this paper analyzes the shortages of the grinding of crankshaft with double apexes,which is used in traditional crankshaft finish machining.In order to keep the crankshaft free of force from double apexes,the flexible grinding method driven by universal coupling is introduced.Secondly,this paper analyzes the shortages of the polishing process of crankshaft with polishing clamp,which is used in traditional crankshaft polishing process.We design a new polishing method with abrasive belt driven by compressed air,which is proven effective through testing in workshop.3.Similarly,inclined oil holes of crankshaft are taken as the research object.This paper analyzes the principle and disadvantages of machining deep holes with HSS(high speed steel)drill or gun drill.Instead of traditional processing equipments and cutting tools,the milling and turning machining center coordinates the new gun drill equipmented with blades,is introduced to research and optimize the processing of the inclined oil holes.Through the research and optimization of the machining process for A23 H crankshaft,it has been applied to the production and actual machining process of crankshaft,and has achieved some economic benefits.