In externally pressurized bearings, forces can be transmitted by means of a fluid film interposed between the two bearing surfaces by an external source. In the conventional types, the equilibrium of external forces and fluid film forces becomes stable by making the fluid flow through external restrictions before entering the clearance space.
In the new types, external restrictions are superfluous. Stability and load capacity are ensured by directing the flow in the clearance space, by means of recurrent grooves on one of the two bearing surfaces, towards a zone where both surfaces are plain.
