Research Development And Application Of Dryer Bearing Fault Diagnosis System For Medium And High Speed Tissue Paper Machine

The developing direction of the medium and high speed tissue paper machine tends to be more continuous,integrated,large-scale,automation and intelligent.The dryer is the core part of the medium and high speed tissue paper machine,thus the stability of dryer heavily impacts the quality and of the produced paper.Also,it is the most important rotation parts for the bearing to allow the operation of the dryer to run stability.Because the medium and high speed tissue paper machine always work within the environment of high temperature,humidity,etc.A serious problem has to be faced that the machine is easy to damaged.Therefore,monitoring and diagnosing the running state of the dryer bearings play an important role to enable the medium and high speed tissue paper machine to run.To address the problem that the vibration signal of the dryer cylinder of the medium and high speed tissue machine is non-linear characteristics as well as traditional vibration signal measuring instrument is quite complex,the concept of virtual instrument is used and an intelligence fault diagnosis system for dryer bearing parts of medium and high speed tissue paper machine has been further developed based on LabVIEW.This study is supported by the Shaanxi Science and Technology Coordination Innovation Project(No.2016KTCQ01-35).The main contributions are as follows:(1)Research on fault characteristics of drying bearingsBased on the research on the vibration mechanism of dryer cylinder bearing of the medium and high speed tissue as well as the structure and failure mode of the double row spherical roller bearing,this study explores the both time and frequency domain features of the inner raceway surface,external raceway and row spherical roller bearing are studied.The time domain characteristics and frequency domain characteristics of the surface and the rolling element surface of double-row spherical roller bearings.Furthermore,this paper proposed the frequency equations of various fault vibration characteristics.(2)Research on external factors of dryer bearing systemThe vibration signals of dryer bearing of the medium and high speed tissue machine are the complex and mixture data,which are produce by structure of the dryer bearing as well as drying cylinder,the water in the dryer,the transmission side motor,the transmission side reducer,and the shaft head vibration and frame vibration,etc.This study does more research on the vibration mechanism and failure vibration mechanism,and the analysis of vibration mechanism of the dryer bearing.These findings provide a theoretical basis for the fault diagnosis of dryer bearings.(3)Design and development of the fault diagnosis systemBased on the design requirements and design principles of the concept of virtual instruments,this study proposed a framework of the fault diagnosis system for the medium and high speed tissue machine,which can be comprised of hardware and software.Hardware includes vibration sensor,signal conditioner,data acquisition card and operation station.In addition,the developed software has been installed on the LabVIEW virtual instrument development platform.According to the use of master/slave design pattern of LabVIEW,the powerful signal processing modules of MATLAB,and the queue functions and cluster functions,the system realized a module that can be used to convert different functions in a custom order.The module can be further divided into six parts: signal acquisition,file management,preprocessing,MATLAB program call,feature extraction and the frequency calculation of fault features.(5)The application of the fault diagnosis system in papermaking factoryThe fault diagnosis system developed based on virtual instrument technology has been applied to monitor the operation status and diagnose fault of dryer bearings of the medium and high speed paper.In comparison to the external factors of the transmission side and the operating side,the vibration signal of the running state of the operating side of the dryer has been used.Furthermore,this study analyzed the vibration characteristics of both normal and abnormal operation.Finally,the fault can be evaluated through theoretical basis of the vibration characteristics of the double row spherical roller bearing.To address the problem of the nonlinear characteristics of the vibration signal and the complex of traditional vibration signal measuring instrument,this study developed a fault diagnosis system for dryer bearing parts of the medium and high speed tissue paper machine based on the concept of virtual instrument and the theory of vibration mechanism and fault characteristics of double row spherical roller bearing.Experimental results and relative application have demonstrated that the developed fault diagnosis system are stable,simple operation,and easy to take and expand.The fault type,reason and location of the failure of the dryer bearing can be obtained after the vibration signals of the running state of the dryer are collected and the effective vibration characteristics are further extracted.