Research On The Dimensional Change Mechanism Of The Inner Ring Of Thin-walled Bearings Of Industrial Robots In Strengthening Grinding Process

The dimension change of the inner ring of the bearing of industrial robot has a great influence on its performance,the roundness change,the radial run-out,the bearing inside and outside diameter size change and so on will affect its performance.The biggest influence on the performance of the bearing inner ring in the intensive grinding process is the dimension deformation of the bearing inner and outer diameters,that is,the bearing thickness changes.The deformation of the inner and outer diameters of bearings mainly affects the diameter change of bearings and causes the clearance change,which makes the bearings unable to be assembled and run normally.This paper focuses on the study of the change mechanism of the inner and outer diameters of bearing rings of industrial robots after grinding at different times.In this paper,the effects of different grinding times on the plastic deformation of the bearing inner ring of industrial robot were studied by using the technology of intensive grinding,changing the injection time of intensive grinding,combining with the classical plastic theory and finite element simulation.By means of intensive abrasive processing test,metallography,XRD and other test methods,microscopic observation and dislocation density of samples with different abrasive intensification times were analyzed,and then the deformation mechanism of samples with different abrasive intensification times was analyzed.The main research contents and conclusions are as follows:(1)Through experiments of intensive grinding processing at different times and combined with simulation analysis,it can be concluded that at the early stage of intensive grinding processing,the plastic deformation layer of the processed surface of the specimen has many uneven convex peaks,which will lead to the thickness of the specimen in the early stage of processing.Industrial robot based on bearing inner ring in the reinforcement of grinding time total deformation rate before and after the test,specimens with the increase of time in processing the first 4 minutes slope into tan150 ° is reduced,to 4 minutes to eight minutes deformation rate increases sharply increased with the increase of time,the growth rate of 8 minutes to 12 minutes,12 minutes after its growth rate has been close with 0,its deformation rate has been stable to three over one thousand.(2)By means of metallographic specimen microstructure analysis,found that with the increase of strengthening milling time,observed under optical microscope specimens wider black area,under the instructions in the reinforcement of grinding process,happened between specimen near the grain processing area of the organization that intertwine,cutting and refinement,in the process residual compressive stress occurs on the surface of specimen making specimen size produced change,as the strengthening of grinding time increasing,further enhance the specimen deformation degree.(3)Through X-ray diffractance test and data analysis using JADE software,the diffraction peak width of Fe and fe-cr phases increases with the extension of injection time,the peak strength of Fe and fe-cr phases decreases,and the diffraction peak width decreases,so the grain refinement phenomenon exists in the intensified grinding.The volume fraction of austenite decreased with the prolongation of processing time.The volume fraction of martensite was in direct proportion to the processing time.With the continuous extension of the processing time,the martensite increased and the size of the specimen changed.However,after 12 min,the volume fraction of martensite and austenite was stable and no longer changed with the processing time.With improved grinding process continuing,the dislocation density increases,the size of the specimen deformation are also increasing,grain size refinement,will lead to deformation of specimen size also increasing difficulty,in conformity with the phase analysis of the data obtained,at the same time as the strengthening of grinding the extension of time,the residual stress grows until it is stable,its change rule in conformity with the law of bearing inner ring size changes,reveals the mechanism of changes of bearing inner ring size.