Noise Analysis And Control For Primary Gears Of Motorcycle Engine

The noise problem of primary gear joggle is becoming more and more serious with the engine of motor developing towards high speed and high intensity. The noise of primary gear joggle not only reduces the comfort of motor, but also influences its life and safety. In order to make the primary gear joggle stable, vibration and noise reduction, while without strong impactive abrasion, it is necessary to analyze and control the noise of primary gear joggle. Based on the primary gears of a single cylinder of a four stroke wind-cooling engine, the article has done study and research on the influence factors on the noise of primary gear joggle through virtual simulation and experiments.Firstly, based on the procreant theory of the vibration and noise of primary gear joggle, the article analyze its dynamic characters to find out the influence of gear parameters and gear shape on the noise. With the use of three-dimensional elastic contact dynamic analyze, research on the critical problems in the virtual simulation of primary gear joggle such as boundary condition, the methods of applying loads and the definition of contact between gear faces, build the finite analyze model of primary gear driven, and carry out the virtual simulation with this model.With the FEA model mentioned, the article analyze the influence of the rotate speed and load in working conditions, gear width coefficient and modification coefficient as well as the modification of tooth shape on the vibration and noise of primary gear joggle. After that it does experiments on the primary gear on the test-bed developed by ourselves. According to the results of virtual simulation and experiments, it draws out the following conclusions:â‘ The vibration and noise of primary gear increase along with the increase of rotator speed, but the increase ratio are different with different modification coefficient, different correction of the flank shape as well as different tooth width.â‘¡Primary gear with different modification coefficient, the vibration and noise are different, the vibration and noise of modification gear is lower with the node locates inside the joggle area.â‘¢The vibration and noise of correction gear is better than the gear without modified, but different correction of the flank shape manner will result in different improvement results, and the line correction is better than circularâ‘£The vibration and noise of small gear width is higher than big gear width, however, the gear width should decided rationally constrained by the production and installation.