Abstract: The load-sharing concept is applied to the dynamic loading model for involute gears, considering the friction and lubrication behavior. To analyze the effect of speed on the dynamic load distribution along line of action, the results are compared with the static model based on the minimum elastic potential energy criterion. The results show that the oil film could weaken the impact load at the resonating speed effectively, while the profile errors make it serious. The film stiffness exhibits strong non-liner characteristics, especially with high ambient viscosity. At lower speed, the dynamic load in average is close to the static model except some visible impacts at the transition points where one-pair-tooth join in meshing or disengage. As speed increases, the impact vibration with high frequency becomes weak, at the same time the dynamic load and relative displacement change more and more periodically. Enhancing the helical angle in some level could reduce the impact phenomenon and the dynamic load peak consequently decreases. The friction coefficient appears higher at the beginning, but with the decreasing dynamic load, the film becomes thicker and the contact ratio of asperities is lower, which leads to a smaller friction coefficient. The rougher the surface is, the higher the friction coefficient would be.

Key words: Dynamic load, Friction, Involute gears, Load-sharing factor, Minimum elastic potential energy