(1) Starting from the friction excitation of the tooth surface, a six-degree-of-freedom accurate gear dynamic model considering the friction of the tooth surface is established. Taking A-type gear as the object of FZG experiment, the time-varying friction arm is analyzed, the actual time-varying meshing stiffness is calculated, and the time-varying friction coefficient is obtained based on the mixed lubrication model, and the variation law of the friction coefficient under different tooth surface roughness is analyzed.
(2) Dynamic differential equation is solved by Rung-Kutta method and gear dynamic characteristics with different friction models are compared. Time-frequency characteristics of gear meshing force, friction force, bearing force and dynamic transmission error under three tooth surface roughnesses are studied based on hybrid lubrication model.
(3) By comparing the two tooth surfaces with FZG test rig, the changes of pinion acceleration signals in meshing line direction, friction direction and box surface are analyzed. The experimental results are in good agreement with the conclusions of simulation analysis.
(4) The results show that increasing the roughness of tooth surface will increase the vibration in the direction of friction force for type A gears studied, and to a certain extent restrain the vibration in the direction of meshing line and reduce the dynamic transmission error. The influence of friction excitation on the dynamic characteristics of gear transmission is further clarified.