When friction is a problem, can air bearings be your answer?

Air-bearing stages are rotary or linear positioners that floats on a cushion of air nearly eliminating mechanical contact, wear, friction and hysteresis effects. Most motion applications are perfectly well-served by mechanical bearing guidance; but where precision, angular repeatability and submicron bearing rumble is problematic, an air bearing stage could be your answer.

Frictionless drive and bearing technology is a prerequisite for vibration-free precision motion with nano-scale resolution, repeatability and guiding accuracy.

Air bearings ensure frictionless motion with guiding accuracies (straightness and flatness of motion) of well below 1 µm over long travel ranges. This precision guarantees optimal part quality and measurement reliability for applications such as flat panel inspection, optics inspection, semiconductor inspection and medical device manufacturing.

Benefits for Air Bearings in motion-control applications
Here are some of the most common factors supporting the use of air-bearing stages for motion-control applications:

  1. Frictionless, accurate positioning
    A direct-drive motor and high-resolution encoder can position a moving carriage supported by an air bearing to within nanometers in a linear application, or within tenths of arc-seconds in rotational applications.
  2. Velocity stability and scanning
    The lack of mechanical bearing elements means there is nothing to get in the way of smooth, controlled velocity (stability to better than 0.01%).

3. Low error motions due to surface averaging effect
Linear air-bearing stages have straight and flat travels; pitch, roll and yaw errors can be measured in tenths of arc-seconds.

4. Long travel requirements
Piezo-driven flexure stages and actuators can satisfy many high-precision positioning applications. However, these designs are usually limited to a few millimeters of travel. Air-bearing linear stages can be used for travels of 25 mm or more.

5. Wobble-free or high-speed rotary motion
Rotary air bearings are exceptionally stiff and can deliver highly precise rotary motion.

6. Minimal maintenance
There are no contacting parts to undergo wear and tear and no regular maintenance procedures to be performed, like lubrication. An air-bearing stage is essentially maintenance-free.

7. Cleanliness
Because air bearings are wear-free, they generate virtually no particulates that can become airborne.

8. Precise force control and sensing
Air bearings are frictionless, which means when they are coupled with a direct-drive motor or voice coil, they work well in micro- and nano-Newton force control applications.