Design Of On-line Rotary Ferrograph And Study On The Image Acquisition Method Of Wear Debris

As an important means of oil analysis,ferrography has been widely used in condition monitoring and fault diagnosis of large mechanical equipment.The traditional ferrography analysis technology is mainly offline,although the analysis results are reliable,the real-time performance is poor.In recent years,some researches have developed on-line ferrograph based on the principle of analytical ferrograph.However,due to the problems of wear debris accumulation and poor image acquisition effect,its application scope has been limited.Aiming at the above problems,a kind of on-line rotary ferrograph is designed in this paper.Analyze the influence of wear debris online collection and image quality factors,for the problem of the high viscosity of the original oil sample and small sedimentary area of wear debris which leads to low deposition rate of wear debris,and residual oil on the surface of the wear debris and the bubbles which causes the edge of the wear debris image is blurred thus affecting the imaging effect,carry on the detailed functional requirements analysis and formulate the overall design scheme for the online rotary ferrography,refine it to sample processing,automatic spectrum,wear particle image acquisition and communication control four modules.Based on the dynamic analysis of the wear debris deposition process of the rotary ferrograph,the parameters of the instrument system related to the wear debris deposition are deduced.The magnetic head with single deposition ring and adjustable magnetic field intensity is designed according to the magnetic head structure of off-line ferrograph,and the sequential deposition of different large and small wear debris is realized.The magnetic field gradient distribution of the magnetic head is simulated and optimized by ANSYS finite element analysis method.The requirements of the on-line rotary ferrograph are analyzed,and the modules of oil sample processing,on-line spectrograph processing and wear debris image acquisition are designed.Among them,the oil sample processing module mainly includes micro pump,air pressure liquid supply device,reagent bottle and oscillating mixer,which realizes the dilution and oscillation mixing of collected oil samples.The on-line ferrogram making module mainly includes the electromagnetic head,the deposition chamber,the supporting shafting and the driving motor,which realizes the on-line ferrogram making of the oil sample.The wear debris image acquisition module includes grinding digital micro-camera and lighting source,which realizes the micro image acquisition of ferromagnetic wear debris.Especially for the limitation that the transmission light cannot be imposed on the online wear debris image collection,a light-field diffuse backlight lighting method combining LED and light guide plate is designed,and the number of LED is optimized through Trace Pro optical simulation based on the uniformity of light illumination.Based on the Lab VIEW software platform,the upper computer communication control software of the online rotary ferrograph is developed,which realizes the remote cooperative control of the oil sample processing,online ferrogram making and image acquisition process,and can simply preprocess the collected wear debris image.Set up online rotary ferrograph bench in the laboratory,use coal winning machine rocker gearbox sample to test online system of ferrogram and image acquisition,use the quantitative analysis and qualitative analysis method,the number,color,shape and texture of the wear debris particles in the ferrogram image are extracted,and the effect of the image acquisition is evaluated.The performance of the wear debris is evaluated synthetically by comparing with the wear debris obtained by off-line ferrography.This paper contains 74 figures,4 tables,and 96 references.