| Compared with other ordinary planetary transmission systems,the compound planetary transmission system has more transmission ratios and more compact structure,so it is widely used in aerospace,navigation and other fields.However,the complex internal structure leads to more obvious noise of the transmission system.At the same time,the gear tooth surface would also evolve into wear,pitting and other faults,these wear and deterioration would further stimulate the internal vibration response,and there is little research on the dynamics and wear of compound planetary transmission system,the basic theory needs to be improved,and many technical problems need to be solved urgently.Therefore,this topic has carried out the following researches on the above-mentioned problems:（1）An experimental platform for the compound planetary gearbox health condition monitoring was designed,manufactured and built,and the normal and different degrees of pitting gear test group scheme was designed for the collection and comparative analysis of vibration and wear information,the equipment and methods for collecting vibration signal,transmission system temperature,surface topography and wear data were introduced respectively,which laid the foundation for subsequent research.（2）For the designed compound planetary transmission system,the time-varying meshing stiffness of normal and different degrees of pitting gears was established and calculated.Then,the nine DOF pure torsional dynamics model of the compound planetary transmission system was deduced and established.The model considers the time-varying mesh stiffness,backlash and damping and other factors,and analyzed the relationship between different degrees of pitting fault and the dynamic response of the transmission system,which lays the foundation for the subsequent improvement of the wear prediction model.（3）Variational Mode Decomposition（VMD）and fuzzy entropy index were introduced,and a vibration signal index extraction method based on VMD and fuzzy entropy algorithm was proposed.The frequency spectrum analysis method and VMD method were used to extract the characteristics of the vibration signals collected in the test process,the accuracy of the dynamic model established in Chapter 3 was verified,and the advantages of the VMD algorithm are judged.The components decomposed by VMD algorithm are used for feature extraction of fuzzy entropy value,and finally the change trend of fuzzy entropy value index was analyzed.（4）According to Archard wear model,the discretized wear prediction model of tooth surface was deduced and established,and the evolution trend of tooth surface wear in different working conditions and time periods was predicted and analyzed.On this basis,the finite element method was used to model and simulate the tooth surface temperature field,and the temperature results are imported into the wear prediction model for improvement and simulation.In addition,the results of the dynamic response simulation are imported into the wear prediction model for improvement and simulation.Finally,the tooth surface wear prediction model under the interaction of vibration and temperature field was obtained,and the effect of temperature and dynamic response on wear was simulated and analyzed.（5）The data processing method of the replica film was introduced,the wear profile of the tooth length and tooth width directions was measured and analyzed,and the wear prediction model in Chapter 4 was verified.According to the research and analysis of the film information in each time period,the wear evolution trend of the tooth surface was analyzed,and the surface topography characteristics of the gear are used as evidence for the research,and the accuracy of the theoretical model was further verified by comparison.Finally,the wear and vibration signals were compared and comprehensively analyzed. |
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