Research On Fault Diagnosis Method Of Planetary Gearbox

Planetary gearboxes have many advantages such as small mass,large transmission ratio,and stable operation,so they are widely used in large and complex mechanical equipment such as wind power generation,helicopters,and mining.As the planetary gearbox has been in the harsh working environment of low speed and heavy load for a long time,this has led to frequent failures of key components such as the sun gear,planetary gear,and ring gear.Once a failure occurs,it will cause huge maintenance costs and cause casualties in severe cases.Therefore,it is of great significance to deeply study the fault diagnosis method of planetary gearbox in combination with the characteristics of the planetary gearbox fault signal.This article takes the first-class planetary gearbox as the research object.The main work contents and innovations are as follows:(1)In view of the complex components of the planetary gearbox fault signal including multiple modulations,and the difficulty of distinguishing the types of local faults,a planetary gearbox fault diagnosis method based on inherent time scale decomposition and permutation entropy is proposed.First,the original signal is divided into multiple data segments,and each data segment is decomposed on the inherent time scale.Then,the sensitive components are screened using the cross-correlation coefficient criterion,and the permutation entropy of the sensitive components is calculated to distinguish the four types of local faults between the sun wheel and the planetary wheel.At the same time,the permutation entropy of sensitive components is calculated,data segments are selected according to the principle of minimum entropy,and Hilbert envelope spectrum analysis is used to realize sun gear fault identification.The effectiveness of the proposed method is demonstrated from both simulation and experiment.(2)Aiming at the diagnosis difficulties such as small characteristic frequency amplitude and frequency multiplication ratio in the partial failure of planeta ry gears,and the amplitude is not prominent,a fault diagnosis method of maximum correlation kurtosis deconvolution planetary gearbox based on parameter optimization is proposed.First,the original signal is de-averaged and preprocessed,and then the parameter filter length L and shift number M of the maximum correlation kurtosis deconvolution are optimized by the feature energy ratio.When the characteristic energy ratio is the largest,the corresponding L and M are the optimal parameter combinations.Finally,the Hilbert envelope spectrum analysis of the signal after the maximum correlation kurtosis deconvolution filter can highlight the characteristic frequency of the planetary gear’s local fault and identify the planetary gear’s local fault.Signal simulation and experimental data show the superiority of the parameter optimization MCKD method.