Study On Vibration Of Marine Planetary Gear Based On Phase Tuning

Marine planetary gear transmission is one of the main equipment of Marine power system,but the vibration produced by planetary gear reducer during operation not only affects its own performance and safety,but also is one of the main sources of Marine machinery noise.The vibration problem poses a great hidden danger to the survivability of ships,and also affects the play of combat effectiveness.It has extraordinary significance and has been concerned by many people.The vibration of the reducer comes from the gear transmission system.Under the background of vibration and noise reduction of the Marine power system,based on the meshing phase tuning theory,the dynamics of the Marine planetary gear system is studied.The effect of the meshing phase on the vibration response of the Marine planetary gear system was obtained by means of theoretical analysis,dynamic modeling and solution,and vibration test of the gear box,and a better phase tuning scheme was proposed based on the actual system parameters.The main content of the thesis is as follows.Firstly,the modeling method of herringbone gear was studied by combining the centralized parameter method and the generalized finite element theory.On this basis,the herringbone planetary gear system was discrete and simplified,and the mechanical model was obtained by considering the flexibility of the shaft members in the system.Considering the degree of freedom in 6 directions of each member,the structure of differential equations of single and two-stage system dynamics was deduced by establishing coordinate system and analyzing the motion and force.Secondly,according to the geometrical characteristics of planetary gear system and the basic principle of gear meshing,the meshing phase was defined by using the length of time-varying contact line of gear meshing.The phase coefficient is introduced to describe it,and the calculation method is analyzed.The dynamic meshing force acting on the central component is analyzed and the analytical relationship between meshing phase and excitation mode is analyzed qualitativelyThen,the free vibration and forced vibration responses of the single planetary gear system with herringbone teeth are calculated by using ROMAX software.Through the analysis of the free vibration response,the distribution law of the natural characteristics of the system is obtained,and the main modes of the system are summarized.By analyzing the forced vibration response of the central component,the response mode is summarized,and the corresponding relationship between "meshing phase,excitation mode and response mode" is obtained.By comparing the forced vibration response with the excitation and natural characteristic mode,the resonance law of the system is analyzed.The theoretical research is verified by the vibration test of gearbox.Finally,the excitation,free vibration and forced vibration responses of the two-stage series planetary gear system were calculated,the inherent characteristics of the two-stage system and the corresponding relationship between "meshing phase-excitation mode-response mode" were analyzed,and the response rules under each excitation mode were summarized.It is pointed out that the phase tuning of the two-stage series system can be converted into the tuning of the first and second stages respectively,and a better tuning scheme is formulated according to the original design of the system.