air bearings
Air Bearings
Basically, air bearings use a thin film of pressurized air to support a load, the same way the puck on an air hockey table "floats" on air. This type of bearing is called a "fluid film" bearing. Fluid film bearings have no solid-to-solid contact under typical running conditions; instead, a film of lubricating fluid (in our case pressurized air) forms a layer between the solid machine elements and serves to transfer forces from one to the other. To compare this with ball bearings, in ball bearings the balls are in constant contact with and form a solid bridge between the machine elements.
Cylindrical air bearings often find use among frictionless rotating supports such as spindles. Our expanding standard product line offers the UTT series universal turntables with nanometric rotational accuracy and remarkably high stiffness (see chart below). Utilizing both cylindrical and thrust surfaces, these bearings provide load capacities up to 230 lbf. Every UTT now features SAFELOCK(tm); a safe and effective way of restricting the rotor without loosing concentricity and parallelism with the stator.
As part of our standard manufacturing process and immediately prior to shipment, each bearing is fully characterized for performance using our custom-designed testing equipment. Automated data acquistion provides consistent, accurate and timely measurement of relevant parameters including: load capacity, flying height, flow rate, vacuum preload, temperature, humidity, inlet pressure, film pressure, barometric pressure, etc. Bearing surface sphericity can be measured using non-contact capacitance probe or laser based interferometric analysis.
In addition to our product line of air bearings, we provide a wide range of sub-contract manufacturing including tools, gages, precision cams, special machines, and prototype or production parts. Our highly skilled technicians combine a profound understanding of precision engineering with the experience of many years; we satisfy and delight customers around the globe. For prompt, personal service, please let us know how we might contribute to your high-precision project.
In an air bearing, the balls are replaced by a cushion of air. Perhaps one of the most familiar applications of an air bearing is a hovercraft. Large fans blow air underneath the hovercraft and the air is prevented from escaping by a flexible rubber 'skirt'. The high air pressure generated under the hovercraft is capable of supporting its weight and it therefore floats on this cushion of air. The large cushion of air not only acts to support its weight but also as a soft spring which allows it to float smoothly over the rough surfaces on land or in the water.
