Study On Dynamic Characteristics Of Gear Coupling Rotor System

Gear coupling rotor system is an important transmission part of the aviation reducer.The study of its dynamic characteristics can provide theoretical basis for the design and optimization of the subsequent reducer.In this paper,the gear coupling rotor system with face gear transmission in the aviation reducer was taken as the research object.The dynamic characteristics of the rotor system were analyzed and the influence of the face gear modification parameters on the dynamic characteristics of the system was studied.The main research contents and innovations of this paper are as follows:(1)The three-dimensional model of the rotor system was established,and the dynamic model of the face gear pair was established by analyzing the nonlinear influencing factors of the face gear pair in the rotor system.The frequency response characteristics of the face gear transmission system under the combined action of internal and external excitation were analyzed by using the multi-scale perturbation method.(2)The vibration characteristics of the rotor system were studied.The modal and critical speed of the single shaft and rotor system,the strain energy of the system modal and the influence of different parameters on the modal of rotor system were analyzed.The results show that after the rotor is coupled into the system,a new mode and critical speed are derived,and the modal frequency is weakened by the influence of speed.The modal vibration of the system mainly comes from the face gear on the low speed shaft.The gear contact friction coefficient,helical Angle of helical gear and installation Angle of high speed shaft only affect the mode derived from the system.The stiffness of the bearing affects all modes of the system.(3)The unbalance response characteristics of the rotor system under the condition of mass unbalance and gear eccentricity were analyzed respectively.The results show that the amplitude of the system increases with the increase of the rotating speed,and the maximum amplitude is the mid-span position of the rotating shaft and the extended shaft end of the rotating shaft.The new modes derived from the rotor system affect the gear eccentricity unbalance response.The gear eccentricity increases the initial value of meshing force and has a great influence on the meshing force in the system.(4)The dynamic simulation of the rotor system was carried out and the influence of face gear modification parameters on the dynamic characteristics was studied.The results show that the angular acceleration at the gear is excited by the medium speed shaft rotation frequency and the meshing frequency of two pairs of gear pairs.Gear modification do not change the frequency interval of each excitation,and the interval is 180.7Hz,which is about 3 times of the rotation frequency of the medium speed shaft.The profile modification mainly reduces the vibration of the system and improves the stability of the system.The length of profile modification has greater influence on dynamics than the maximum amount of profile modification.Axial modification mainly reduces the average value of angular velocity and meshing force of the system.