Simulation Research On Sun Gear Crack,Breaking And Mixing Fault Of A Planetary Gear Box Based On Rigid-flexible Coupling Model

Using the virtual prototyping technology,the single-stage planetary gearbox under the normal,crack and broken teeth of the experimental sun gear is taken as the reference object,and the rigid-flexible coupling model is established and the dynamics simulation is carried out.By comparing the simulation results with the experimental results,Verify the correctness of the simulation model.After the model verification is successful,the vibration characteristics of the planetary gearbox under different conditions of different degrees of cracks,different degrees of broken teeth,cracks and broken teeth of the sun gear are simulated and studied systematically.The specific work content is as follows.(1)The rigid-flexible coupling simulation model of the planetary gearbox that can extract the vibration acceleration signal from the surface of the box is established by Adams software.The contact parameters of the simulation model are selected by constructing a new parameter "modulus of rotational speed-transmission ratio relative error vector",and the kinematics performance of the simulation model is judged by using MD image.Finally,the correctness of the rigid-flexible coupling simulation model of the planetary gearbox is verified by comparing the spectrum of the simulation and experimental signals.(2)Taking the sun gear crack of the planetary gearbox of the experimental platform as the research object,the fault model with the same degree of cracking of the sun gear of the experimental platform and the different degree crack fault model of the sun gear were built and simulated based on Adams.The ? index of the frequency band similarity of the sideband is proposed,and the sun gear crack fault model is verified by using this index.By comparing the simulated signal with the experimental signal,?=64.5%>50.0%,which verifies the effectiveness of the crack fault simulation model.Finally,the time-domain and frequency-domain vibration characteristics of crack cracks with different degrees of cracking are studied.Based on the time-domain vibration characteristics,the variation of each time-domain index with the degree of crack failure is analyzed and summarized.(3)Based on the fracture form of the planetary gearbox sun gear of the experimental platform,the fault model with the same degree of the sun gear breaking of the experimental platform and the fault model of the sun gear with different degrees of broken teeth are established and simulated.In the verification of the sun gear broken tooth failure model,comparing the simulation signal and the experimental signal,the ?=77.1%>50.0%is obtained,which verifies the effectiveness of the broken tooth fault simulation model.The vibration characteristics of different degrees of broken teeth faults are studied.The time-domain and frequency-domain vibration characteristics of different degrees of broken teeth faults are obtained,and the regularity of each time-domain index with the degree of broken teeth is summarized.(4)Based on the 90.0% crack failure model of the sun gear and the different degrees of broken tooth failure models,six fault models with crack and broken teeth were established and named as Model 1 to Model 6.The dynamic simulation calculations of these six hybrid fault models are carried out,and the following conclusions are obtained: 1)The maximum amplitude of vibration acceleration of the hybrid fault model increases with the increase of the model number.2)Analyze and summarize the rules of each time domain index changing with Model 1 to Model 6.3)The amplitude at the meshing frequency increases as the model number increases.Under the condition of 90.0% crack failure,the gear teeth have a greater impact on the system when the gear teeth are broken half and fully broken.