In an aerostatic bearing, the two bearing surfaces are separated by a thin film of pressurised air (see figure). The air is supplied between the surfaces by one or more nozzles in the bearing. The distance between the bearing surfaces is about 5 to 30 Ám. As the object is floating on a thin layer of air, the friction is extremely small and even zero when not moving.
Air bearings have the following characteristics and advantages:
In contrast to aerodynamic bearings, aerostatic bearings can bear loads at zero speed. With a correct design, very high stiffness can be obtained. Air bearings offer a solution for many high-tech applications: where high-performance and high-accuracy are required.