02-03-2017, 10:43 AM
Air bearings (also known as aerostatic or aerodynamic bearings) are bearings that use a thin film of pressurized air to provide an extremely low friction loading interface between surfaces. The two surfaces do not touch. As they are free from contact, air bearings avoid traditional friction bearing, wear, particle and lubricant handling issues and offer distinct advantages in precision positioning such as lack of play and static friction as well as in high Speed Applications.
The fluid film of the bearing is air flowing through the bearing itself to the bearing surface. The design of the air bearing is such that, although air escapes constantly from the bearing gap, the pressure between the bearing faces is sufficient to withstand the work loads. Thus, there is a differentiation that has to be made between the aerodynamic bearings, which establish the air cushion through its movement, and the Aerostatical bearings, in which the pressure is being inserted externally. Air bearings are being used mainly in precision machinery tools (measuring and processing machines) and fast-running machines (high-speed spindles).
Basically, air bearings use a thin film of pressurized air to support a load, much like the puck on an air hockey table "floats" in the air. This type of bearing is called a "fluid film" bearing. The fluid film bearings do not have solid-solid contact under typical operating conditions; Instead, a film of lubricating fluid (in this case pressurized air) forms a layer between the solid elements of the machine and serves to transfer forces from one to another. To compare this with ball bearings, in ball bearings the balls are in constant contact with and form a solid bridge between the elements of the machine.
The fluid film of the bearing is air flowing through the bearing itself to the bearing surface. The design of the air bearing is such that, although air escapes constantly from the bearing gap, the pressure between the bearing faces is sufficient to withstand the work loads. Thus, there is a differentiation that has to be made between the aerodynamic bearings, which establish the air cushion through its movement, and the Aerostatical bearings, in which the pressure is being inserted externally. Air bearings are being used mainly in precision machinery tools (measuring and processing machines) and fast-running machines (high-speed spindles).
Basically, air bearings use a thin film of pressurized air to support a load, much like the puck on an air hockey table "floats" in the air. This type of bearing is called a "fluid film" bearing. The fluid film bearings do not have solid-solid contact under typical operating conditions; Instead, a film of lubricating fluid (in this case pressurized air) forms a layer between the solid elements of the machine and serves to transfer forces from one to another. To compare this with ball bearings, in ball bearings the balls are in constant contact with and form a solid bridge between the elements of the machine.