In the elastohydrodynamic state, the elastic approaching amount of the contact body is a comprehensive result of the change in oil film thickness and the elastic deformation of the contact body itself, which is different from the concept of Hertz contact approaching amount without considering lubrication.
(b) Equivalent elastohydrodynamic contact model
Figure (a) shows a schematic diagram of the tooth profile contact of a pair of involute spur gears under elastohydrodynamic lubrication, with an elastohydrodynamic oil film separating the two tooth surfaces at contact point K. From the perspective of elastohydrodynamic research, Figure (a) can be equivalent to the elastohydrodynamic lubrication contact model shown in Figure (b).
In Figure (b), the entrainment velocity u and the comprehensive curvature radius R are:
In the equation, ω 1、 ω 2. The angular velocity of the main and driven gears, (°)/s); R1 and R2 are the curvature radii, m, of the main and driven gears, respectively.
Given the parameters of the spur gear pair and lubrication parameters, the stiffness of the elastohydrodynamic friction pair of the spur gear at the meshing point K can be obtained.