Study On Key Technical Problems About Combined Machining Of Large Bearing Raceway

Large bearing,as the basic part in heavy equipments,affects working performance of main equipments directly.With the rapid developing of modern industry,the large bearings have been expected to have long life,high precision,high load capacity.The quality of large beating is affected by many aspects such as material,processing equipment,processing method,ect.The surface quality of raceway is the most important of them which is directly related to the working performance of the large bearing,so the final processing is very important.Traditionally,the final processing of the large bearing is fine grinding or polishing after grinding,but it has some deficiencies such as bad surface quality, unstable surface quality,long processing time,ect.So it is very hard to meet the requirement of the large bearing raceway machining.This thesis suggests electrochemical abrasive belt machining(ECABM),which machines by the interwork of electrochemical anode dissolution and the "cold,flexible" polishing of abrasive belt,to finish the large beating raceway.According to the key technical problems of ECABM when machining large bearing raceway,this paper did comparatively sufficient research theoretically and experimentally.First,studied on the basic principle of ECABM,analyzed the micro-planning theory, obtained the machining parameters which are important to the final surface quality.Then,according to the ECABM of large bearing raceway,the machining device had been devised which includes general structure,electrolyte circulating system,passive film removing abrasive belt device,cathode tool,and using fluid dynamics software FLUENT to simulate the machining flow field which helps to improve the cathode structure.At last,by the premise of simulating large bearing machining condition,taking small metal ring as specimen,established the experimental device of ECABM.Through the electrolyte experiment,the composition of the electrolyte had been determined which leads to high machining quality and high machining efficiency.Through orthogonal experiment and single factor experiment,the matching relationship of the processing parameters had been fully researched.The experimental results show that using the optimum seeking parameters, the surface roughness of the specimen can be reduced to Ra0.03μm from Ra0.6μm.The optimum seeking parameters are also suitable to the large beating raceway machining using ECABM,which can avoid the expensive,inconvenient and blind experiment using large bearing as specimen directly.Introducing ECABM to the large bearing raceway finishing which can replace traditional grinding and superfinishing,could obtain good raceway surface quality.It is beneficial to overcome the deficiencies of large bearing raceway final processing,improve the working performance and lifetime of large bearing.