A Finite Element Analysis of OAV Air Bearings Used in Ultra-high Speed Spindles
"Imagine you have a spindle that can run over 500K plus RPM, less than 1 millionths of an inches (.025 microns) precision with no oil or maintenance required... PRICELESS "
“Frictionless” Air bearings continue to be a fascinating development for the machine world! Among knowledgeable developers and designers air bearings have created an immense curiosity and appreciation for their benefits. A spindle application is just one of many possible uses for air bearings in the machine development industry.
There is no difference between the static and dynamic coefficients of friction in air bearings, and hence No contact between the surface, no slip-stick phenomenon, virtually No heat generation, No wear, and most important, no maintenance. The elimination of maintenance on the air bearings is invaluable in so far as the reduction or elimination in down time, the reduction in required maintenance labor, and the reduction in replacement costs makes them extremely cost effective.
Air bearing “friction” is a function of air shear from motion. Therefore at zero velocity, there would be zero friction making infinite motion resolution theoretically possible. However, we account for coefficient of friction in log scale .000008 due to the motion of air molecules and gravity. For extremely high-speed applications, coupled with the creative use of specialized materials and, when applicable through the use of OAV’s temperature-controlled air bearings we are able to maintain a constant temperature of the bearing.
OAV Temperature controlled Air Bearings are able to maintain similar mechanical properties at very low and very high temperatures. Factoring in Material type, fluid flow, and airflow, OAV engineers can adjust the Air bearing design to keep them at a constant temperature so machines can operate under extremely high speeds, high ambient temperatures, and hot applications without sacrificing precision or quality.
In addition to the above, OAV Air bearings have higher stiffness and excellent geometric performance. The OAV Thrust Air Bearings preload both horizontal and vertical surfaces with opposing thin-film pressure. This maintains the perfect gap of ultimate tolerance. OAV’s Air Bearing surface design equally distributes the air over the entire surface area resulting in outstanding stiffness and maximized performance.
Controlled spindle Temperatures
Higher Load Capacity
Lock of Maintenance
Ultimate Tool life
Superior surface finish
No vibration, reduce post-machining finish work
Many reasons, OAV Thrust Air Bearings and OAV Roller Air Bearings, are an excellent choice for spindle applications.