Research On The Effect Of Phase Adjustment And Meshing Impact On Noise Radiation In Planetary Gear Transmission

The main advantages of double helical gear transmission contain high transmission efficiency, compact structure, as well as high loading capacity which make it widely used in aerospace, industrial and marine ships. The vibration and noise problems of the system are serious due to the complicate structural parameters and working conditons. Hence, the dynamics and noise issues of planetary gear transmission are very important. In this paper, a noise reduction solution is researched based on phase adjustment in planetary gear transmission. Then, the effect of meshing impact on noise radiation is also researched. At last, the noise reduction based on phase adjustment is demonstrated by a comparative experiment, which shows the validity of the method.Firstly, a bending-torsional dynamic model and vibration differential equations are constructed based on lumped-mass method. The dynamic load of the bearing is calculated and analyzed by the vibration differential equations.Secondly, modal frequency and vibration response of the gearbox are computed by the finite element method. By using the method of the boundary element method, the acoustic radiation pressure level of the gearbox is computed with boundary conditions imported from the result of vibration response.Thirdly, based on theory of phase adjustment, this paper deduces the formula for calculating the three mesh phase coefficients of the planetary gear transmission and then obtains the condition of no phase difference. After meshing stiffness where the phase difference is considered is analyzed, the relation between the design parameters and the vibration form and noise radiation of the transmission can be obtained.Then, the geometrical model of meshing impact,as well as formula for calculating impact is created. The effect of the loading conditions on impact and the influence of the impact in different loading conditions on the planetary gear transmission are analyzed.Finally, two pieces of planetary gear are designed. To verify noise reduction solution method of phase adjustment, the signals of vibration and noise radiation of planetary gear transmission are measured in accordance with the test program. Analysis results indicate that method of phase adjustment is beneficial to reduce the noise radiation of planetary gear transmission.