Study On Non Destructive Testing Technology Of Inner Diameter Of Single Lip Sealing Ring

At present,the maintenance system of China's emu is still based on planned preventive repair.The single lip sealing ring in the gearbox of the emu train is an indispensable non-metallic accessory for the normal operation of the train traction system.During the maintenance of bullet train,the inner diameter of the single lip sealing ring in the gear box should be tested to determine whether it needs to be replaced.The traditional contact measuring method can deform the inner diameter of the single lip sealing ring and cause a large measurement error.Therefore,the main research contents and innovations of the inner diameter detection of the single lip seal ring are as follows:At present,the maintenance system of China's emu is still based on planned preventive repair.The single lip sealing ring in the gearbox of the emu train is an indispensable non-metallic accessory for the normal operation of the train traction system.During the maintenance of bullet train,the inner diameter of the single lip sealing ring in the gear box should be tested to determine whether it needs to be replaced.The traditional contact measuring method can deform the inner diameter of the single lip sealing ring and cause a large measurement error.Therefore,the main research contents and innovations for the detection of the inner diameter of the single-lip sealing ring are as follows:(1)To study the two traditional NDT methods: large tool microscope agglutination test and optical image measuring instrument,and by using two methods of NDT testing single lip seal samples inside diameter size,make a comprehensive comparison,the results show that large tool microscope test accuracy of 10 microns,the average detection an artifact time-consuming 2 min.The detection accuracy of the optical image measuring instrument method is 3 microns,and the average detection time of a workpiece is 1.5 minutes.(2)A set of automatic focus visual nondestructive testing device is designed based on machine vision technology.The detection device is mainly composed of imageacquisition,mechanical and electrical control,autofocus,image processing and output.(3)In order to realize fast and accurate focus of the lens in the process of image acquisition,the energy gradient threshold function of "four neighborhoods" was taken as the automatic focus evaluation algorithm to design the automatic focus control system.The system is mainly composed of image acquisition module,motor drive module and image processing module.(4)A variety of image processing algorithms were analyzed for the inner diameter of the single lip sealing ring.Finally,multi-angle diameter measurement method was selected to characterize the collected inner diameter through comparison.The algorithm program of the integrated detection device designs a human-machine interface.When the interface is used to detect the single-lip sealing rings of different specifications,it takes about 45 s on average to detect a workpiece after the process of autofocus and image processing is completed.(5)In this paper,the accuracy and efficiency of three non-destructive testing methods were compared.The results showed that: the large tool microscope testing method relied on manual testing,with low detection efficiency.The single piece testing took about 2 minutes,and the detection accuracy was 10 microns.The detection accuracy of the optical image measuring instrument method is the highest,up to 3microns,and the automation level is higher than that of the large tool microscope method.Compared with the other two non-destructive testing methods,the automatic focus visual non-destructive testing device designed in this paper is faster,more efficient,single piece testing takes about 45 s,and has strong data traceability,which is more suitable for batch non-destructive testing and batch maintenance testing of inner diameter of single lip sealing ring.