Research On Transmission Gear Tooth Profile Modification And Noise Vibration Characteristics

The gearbox is one of the most important components of the vehicle power system. As amiddle power transmission link, it plays a key role in adjusting vehicle speed and torque, sothe stable working condition is very important. With the progress of society, People raisedhigher and higher requirements for passenger cars. A fast, comfortable and quiet drivingexperience is popular. As an important part of the gear transmission, the gear determines thesmooth functioning of the transmission quality and functionality. This article began writingfrom involutes gear tooth profile modification. Discuss that how to achieve the purpose ofreducing vibration and noise through the gear tooth profile modification; The noise reducethat the gear after repair is proved by time-frequency analysis method and the sound featuresof gear transmission mechanism which in different speed is analysis out by frequencyspectrum; Finally, the time-series methods was applied to the surveillance of the gear lifetimeand eliminate hidden dangers before gear failure.The noise in the process of the gear teethmeshing is caused by vibration. The vibration model of gear and gear vibration wasestablished.In the involutes gear tooth profile curve, the vibration was taken into account, andcoupled a gear tooth profile on the top of the teeth and the root part of the tooth profilemodification curve. In order to reduce the gear meshing and the meshing impact strike,vibration and noise reduction of running gear effect.This device and method for detecting, the modern characteristics of signal acquisitionwere illustrated. The modification of gear were taken as the research object, the two differentsound signals were collected. The sound file was analyzed by MATLAB software. Threekinds of noise arising from the meshing, bearing operation and in the process of motor running out were separated by using Butterworth digital filter.Analysis of gear tooth profilemodification gear meshing noise waveform shape difference before and after the gear toothprofile modification. And then analyze the bearing and motor noise sonic shape and analysismethod of reducing noise. The sound files was transformed by fast Fu Liye transform (FFT)and the time domain is converted to the frequency Spectrum, the spectrum was analysised anddiscussed during gear transmission with speed. The frequency was changed to improve themechanism of the noise, and the reason was analysised.The nonlinear time series model was lead by time series analysis theory. this way wasmore superiority and convenient than the conventional adaptive.The method is applied to thewhole life management, monitoring of gear transmission mechanism. Time series model ofsmall displacement of the vibration in gear transmission were established in this paper. Thesmooth surface and worn surface were established respectively.Then, the time-domaindiagram and the corresponding time series model prediction curve was draw by MATLAB.The nonlinear time series was validated on prediction of gear transmission in the instabilityand failure. The micro displacement of the two gear meshing process was compared andanalyzed the reasons. The time domain chart and the prediction curve of a helical gear underthe same conditions were made. The difference of spur and helical gears in the runningstability was compared and the reason was explained.