Research On Gear Modification Of Planetary Gear Transmission

The herringbone planetary gear transmission contains compact structure,high transmission efficiency,as well as high loading capacity.These advangtages metioned above make it widely used in vehicles’ gearbox,marine equipment and so on.With the request for heavy loading capacity of planetary gear transmission becoming higher and higher,researchers put more attention on the methods for noise reduction.In this paper,modification of a single herringbone planetary gear transmission are studied and a comparative experiment is carried out.Firstly,a three dimensional model of planetary gear train is established by using ROMAX Designer.Taking the deformation in the gear meshing process and meshing skew into consideration,the amount of modification are limitted in a certain area of reasonable scale.The exact amount of modification are obtained according to the distribution of gearing mesh mark or loading when these scales have been applied to the model.Secondly,a translation-torsional coupling nonlinear dynamic model of herringbone planetary gear train is established by lumped-mass method.Vibration differential equations are deduced.The acoustic radiation pressure level and noise spectrum curve of the system with modification are calculated by the methods of the boundary element and finite element.The effectiveness of tooth profile modification to reduce vibration noise can be proved compared with the system without gear modification.Thirdly,the comparative experiments are carried out.Noise Signals are obtained.Analysis results proves that the method of gear modification is helpful in reducing the noise of herringbone planetary gear transmission.