Vibration Source Detection System Of Gearbox Based On Vibration Signal Propagation Path

As a transmission device, gearbox is widely used in the modern industry, theaccurately identify of the fault source signal is important to machine monitoring and faultsdiagnosis. Based on the National Nature Science Fund Project (NO:50905050), research onthe gearbox vibration source detection system based on the vibration signal propagationpath was carried out. On the basis of analysis of the mechanism of the gearbox vibrationsource system, source identification methods and the transfer function, the phase change ofattenuation of the mechanical vibration signal at the same species and different kinds ofphases based on the propagation path of the gear box were researched, and studied thetheoretical simulation and experimental verification. Finally, corresponding vibration sourcedetection system based on the experimental study of the theory on the front was developed,and the practical application verification was done. The details were as follows:In Chapter one: The significance of the gearbox fault diagnosis in the fault diagnosiswas discussed, described the multidisciplinary study of the fault diagnosis in thedevelopment process, analyzed the deficiencies of the existing theoretical approachestroubleshooting, proposed a new framework to detect the vibration source signals based onthe signal propagation path. The common time-domain analysis, frequency domain analysisand time-frequency analysis method were analyzed by contrasting research status at homeand abroad. Comprehensive comparative analysis of the feasibility study of fault diagnosisbased on signal propagation path and the significance of the subject were discussed. Finally,the research technology roadmap and overall structure were elaborated.In Chapter two: The main failure modes and failure characteristics of the gearbox werediscussed, the vibration mechanism of gearbox parts were analyzed. The source parametersof gearbox were analyzed for theoretical modeling. Suitable vibration source identificationmethods based on the signal propagation path was discussed by analyzing the relationshipbetween source parameters and responses. Transmission path of vibration signal and itsimpact on signal transmission in the gear box were analyzed. The changes of vibrationsignal in the gearbox were analyzed from the perspective of transfer function, and ameasurement method of the transfer function based on Hammer was carried out.In Chapter three: With gear box for the study, the propagation characteristics ofmechanical waves in the same type of media were analyzed, dynamic Simulation wasresearched. The propagation changes of the mechanical wave in uniform rod, the rod and cone axis of rotation were researched through theoretical modeling and simulation softwaresuch as ANSYS Workbench and MATLAB, etc.In Chapter four: With gear box for the study, the propagation characteristics ofmechanical waves in the different types of media were analyzed. The suitable theoreticalmodel was selected for the research on the attenuation changes of the mechanical wavethrough the solid-liquid and solid-vapor phase in the gearbox.In Chapter five: A suitable test system was constructed on the basis of the previoustheoretical research. The attenuation changes of vibration signal in the propagation path ofthe gear box were analyzed by building a controllable source of vibration system which wasalso used for the research on the sensitivity of the fault signal source in differentpropagation paths. Finally, a recognition system of source signal in the gearbox based on thesignal propagation path was constructed.The conclusions and inadequate are presented and some advanced topics in theproposed methodology that needs further investigation in future are presented andaddressed.