Air bearing

The two surfaces do not touch, thus avoiding the problems of friction, wear, particulates, and lubricant handling associated with conventional bearings, and air bearings offer distinct advantages in precision positioning, such as lacking backlash and static friction, as well as in high-speed applications.

Among these two technological categories, gas bearings are classified depending on the kind of linkage they realize: The main types of air bearing fall under the following categories: Pressurized gas acts as a lubricant in the gap between moving parts.

Supplying gas to the interface between moving elements of an aerostatic bearing can be achieved in a few different methods:[4] There is no single best approach to feeding the film.

[5] Dead volume refers to chambers and canals in conventional aerostatic bearings, as well as the cavities within porous (sintered) materials, that exist to distribute the gas and increase the pressure within the gap.

However, in order to allow a uniform gas pressure even with few nozzles, aerostatic bearing manufacturers take constructive techniques.

This design assumes that with a limited amount of nozzles, the dead volume should decrease while distributing the gas within the gap uniformly.

[9] Laser-drilled micro-nozzle aerostatic bearings make use of computerized manufacturing and design techniques to optimize performance and efficiency.

Rather than a few large nozzles, aerostatic bearings with many micro-nozzles avoid dynamically disadvantageous dead volumes.

The physical behaviors of the air bearings prove to have a low variation for large as well as for small production volumes.

Unlike liquid-lubricated bearings, the gas lubricant has to be considered as compressible, leading to a non-linear differential equation to be solved.

Fat- and oil-free drives for respirators, stick-slip-free movements of scanners or a high rotary speed of large rotors have all been achieved with air bearings.