| High-speed flexible planetary gear transmission systems are widely used in heavy machinery,aviation,automobiles,wind power and other industrial fields due to their compact structure,small size,and high power density.However,various problems are prone to occur,and even system failure is caused due to insufficient research on the dynamic mechanism.In view of this,this paper takes the planetary gear transmission system as the research object,comprehensively considers the influence of the gear housing,ring gear and other components flexibility and unsteady working conditions,and establishes the coupling dynamics model of the high-speed flexible planetary gear transmission system.The dynamic characteristics and load sharing characteristics of the planetary gear transmission system are deeply studied,which lays a foundation for improving the dynamic performance of the equipment.The specific research contents are as follows:(1)The planetary gear system is transformed into a fixed-axis gear system sun gear-planet gear meshing pair(external meshing)and planetary gear-ring gear meshing pair(internal meshing)under the moving coordinate system oxyz;By discretizing the contact line of the meshing pair and superimposing the meshing force of each discrete point,the calculation method of the meshing force is deduced;Considering the influence of non-inertial frame,the lumped parameter dynamic sub-model of sun gear and planet gear is established;.Based on the reduced-order model method,reduced-order sub-models of flexible components such as ring gear,gear housing and planet carrier are established.Both types of sub-models take into account the centrifugal force and inertial force of rotating components.The system dynamics model is formed by the coupling relationship between force,displacement and velocity between lumped parameter sub-models and reduced-order sub-models.(2)Based on the established planetary gear dynamics model,the natural frequency and mode shape of the system are obtained,the change of the natural frequency under different meshing phases is studied,the typical natural mode shape is described,and the influence of the gear housing on the natural characteristics of the system is analyzed;The dynamic response of the system under steady-state,high-speed and accelerated conditions is obtained,including the vibration displacement,dynamic meshing force and dynamic bearing force of the main components.The influence of the gear housing and various error excitations on the dynamic response characteristics of the system is studied from the perspectives of the time domain and the frequency domain.(3)Based on the dynamic meshing force of the internal and external meshing pairs under each working condition,the load sharing coefficient under each working condition is obtained.The influence of the gear housing and various error excitations on the load sharing performance of the system is analyzed.(4)The planetary gear transmission system test bench was built,and dynamic experiments under different working conditions were carried out.The vibration acceleration signals of the sensors at each measuring point were collected.By means of the time domain spectrum analysis of the signal,the influence of rotational speed and torque on the dynamic characteristics of the planetary gear transmission system is studied.The correctness of the planetary gear dynamics model established in this paper is verified by comparing the experimental data and the simulation data in the time domain and frequency domain. |
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