Research On Traceability Method Of Gear Noise In Automobile Gearbox

Gear noise detection and traceability technology is one of the important methods to improve the quality of automotive gearboxes.Gear noise traceability is the identification of gear noise sources by analyzing the characteristics of noise signals.However,the complexity of noise signals itself brings some difficulties to feature extraction.For this purpose,this paper takes the gears and its noise of automobile gearboxes as research objects,and carries out research work on gear noise traceability methods.The purpose is to solve the problem that it is difficult to extract the characteristics of noise source signals,and to provide an effective criterion for the identification of noise source types.Firstly,this paper analyzes the mechanism of gear noise generation from the basic theoretical aspects,and classifies the gear noise sources accordingly.Then,this paper explores the various excitation sources that cause gear noise and the frequency composition of noise signals by establishing the gear dynamic model,and focuses on the signal characteristics of the various noise sources of the gear.Secondly,this is the theoretical study of the source tracing method in this paper.Based on the Variational Mode Decomposition(VMD)algorithm,this paper proposes a K value optimization method based on the Gini impurity based on the question that the modal decomposition number K directly affects the decomposition effect of the algorithm.This method calculates the Gini impurity and its growth rate under different K values,uses the threshold of 1% as the selection index of the best K value.In addition,the power spectrum and detailed spectrum analysis based on the noise signal are introduced.The paper makes a detailed analysis of specific component signals from the perspective of energy,making the characteristic frequencies of the signals more obvious.Theeffectiveness of the gear noise traceability method is verified by analyzing the simulation signals.Lastly,this is the experimental verification part of the method proposed in this paper.In this paper,the self-designed gear noise test bench is used to collect the noise signals of the first-stage transmission gear pair(drive gear and idler gear)to realize the traceability and identification of gear wear noise and crack noise sources.The experimental results show that the method can extract the characteristic frequency of the specific noise source signal,and it is consistent with the theoretical analysis characteristics.Based on the combination of theoretical analysis and experimental verification,this paper studies the feasibility of the noise source tracing method for automobile transmission gears,and achieves effective identification of specific noise sources of automobile transmission gears.It has practical significance for the later research on vibration reduction and noise reduction of automobile transmission and early fault diagnosis of gears.