Abstract: Aiming at the effects of ladder-shaped parameters for double involute gears on elastohydrodynamic lubrication, the formulas of the contact line and the radius of equivalent curvature were proposed based on the tooth profile and elastohydrodynamic lubrication theory. The variation of the minimum oil film thickness and friction coefficient in the meshing period was obtained by numerical calculation. The elastohy drodynamic lubrication model of double involute gearuas estaldished, and the influence of step parameters of double involute gear on elastohydrodynamic lubrication characteristics was studied. The results indicate that the minimum film thickness obtained by the model is slightly different from the numerical results obtained by the example and empirical formulas. Compared with the height coefficient, the tangential displacement coefficient has less effect on the minimum oil film thickness, and the minimum film thickness decreases with the increase in the height coefficient. The friction coefficient increases with the increase in height coefficient and decreases with the increase in tangential displacement coefficient.
Key words: double involute gear; elastohydrodynamic lubrication; ladder-shaped parameters; oil film thickness; friction coefficient