EHD lubrication of point contact
Elastohydrodynamic Lubrication

Under load, the contact area increases and becomes elliptical (see figure 8 ).

By reducing one of the two surfaces to a plane, the contact is equivalent to a barrel-plane contact, which will have the same elliptical area and pressure field as the actual contact. The barrel has two main radii of curvature, which we will note Rₓ in the direction of the bearing and R _y in the direction perpendicular to the bearing.