Aerostatic bearings

The function of aerostatic bearings is to allow for guidance in rotation or provide axial supports with a bearing capacity at nil rotation speed. Air, which is always available remains the most used lubricant in these systems. This article presents the main static and dynamic qualities of aerostatic bearings. Simplified methods allow for their calculation but as they remain quite imprecise recoursing to digital methods lead to much better results. The general design rules based upon knowledge of the physical mechanisms involved remain essential. Regarding aerostatic bearings, the risk of pneumatic instability adds up to that of aerodynamic instability which is typical for high rotation speeds.