Research On Vibration Characteristics And Diagnosis Of Gear Broken Teeth-pitting Compound Fault

Gear box at the core of many large mechanical transmission parts, Such as wind turbines growth box tanks, a helicopter main gear reducer, transmission system, etc. it is played a vital role in the whole mechanical operation. Owing to the various harsh environments, it is happened to various faults, especially the gear faults accounted for large proportion and gear broken teeth and pitting is also one of the most common and most easy to appear. gear broken teeth and pitting fault, not only will occur alone but also at the same time often may lead to broken teeth-pitting compound fault, if not in time to do fault diagnosis, it can become to lead to the gearbox failure as well as the whole machine, and even bring huge economic losses and human casualties. gear broken teeth-pitting compound fault as the research object, It is to analyze vibration characteristics and Using manifold learning method to get the link features between the compound fault and single fault of the different degree.Through summarizing different types and different degrees of fault characteri stics, finally achieving the purpose recognition.the main research work as follows:(1) Based on ADAMS, broken teeth-pitting compound fault dynamics modeling.Spectra Quest company(USA) integrated fault simulation test bench gearbox is as for the object. Setting up the gear contact parameters in ADAMS, gear meshing stiffness is obtained by calculation which needs many times simulation optimization to get the closest to actual meshing stiffness and damping. Analyzing the main deformation type and its characteristthe in the meshing movement, By introducing the auxiliary gear to solve modeling problem of the bending deformation of gear and gear torsional deformation, using the implant fault geometry which contact algorithm is effective in the ADAMS software to simulate the gear contact deformation, Gear fault of single and compound was studied on the influence of gear transmission system. setting up the gear broken teeth-pitting compound fault and the single of dynamic models.(2) Gear broken teeth-pitting compound fault on vibration characteristics analysis and research on diagnosis methods.firstlly, on the basis of the dynamic model for gear fault, through setting up the simulation conditions to get the response signal of broken teeth signle fault, pitting single fault and compound fault. Secondly, based on the timedomain statistical indicators of 12 characteristic parameters to get the dynamic characteristics of gear broken teeth fault and pitting single fault, through optimizing time domain feature parameters to analyzing broken teeth-pitting compound fault in four different levels, three different load, and three different speed. Finally, broken teeth single fault, pitting single fault and compound fault is analysed by spectrum, and puts forward the gear fault diagnosis method based on the level of absolute deviation. compared with normal state, which can get different levels and different types of fault in the meshing frequency several times frequency what is most sensitive, on the basis of summarizing the characteristics of the fault signal which can reach the purpose of fault identification.(3) The link feature analysis between broken teeth-pitting compound fault and the single fault. the use of manifold learning method for data analysis, in different degrees and under different rotational speed of gear tooth broken,to get pitting intrinsic characteristics of the single fault and compound faults and its change rule. Through the link between broken teeth-pitting compound fault and the single fault feature analysis and its change law to find with the degree of fault, fold zone between single fault and compound faults gradually become smaller, its associated degree gradually weakened, broken teeth single fault and compound fault which can be very good recognition in the early and late fault, and pitting fault single and compound fault can achieve good recognition effect in late fault.to find which for overall broken teeth single fault circle area is relatively concentrated, especially in the early fault and late fault, and pitting single fault circle area and compound fault are an obvious change, and pitting single fault feature is obvious only in the early fault.to find along with the speed of change, broken teeth single fault and compound fault which circle the center of curvature attachment are in increases gradually, and there is no change for pitting single fault.summarizing the fault feature, combined with time domain and frequency domain analysis to get the conclusion, finally achieving identification purposes of different degree between compound fault and single fault.(4) Broken teeth-pitting compound fault experiment.Spectra in the United States the fault simulation test bench is to be as the object to collect experimental data, Gear transmission system dynamics model is proved to be correct. the gear fault diagnosis method based on the level of absolute deviation is to be correct. the link between broken teeth-pitting compound fault and the single fault feature analysis is to be correct.