Report on Air bearing

2.  An air bearing is a non-contacting system where a gas
film (typically air) acts as the lubricant that separates
the two surfaces in relative motion.
 Air bearing technology offers real advantages to
applications where the demand for accuracy, speed and
reliability is crucial.
 air bearings avoid the traditional bearing-related
problems of friction, wear, and lubricant handling, and
offer distinct advantages in precision positioning and
high speed applications.

3.  There are basically two types of air bearing:
1)Aerostatic 2)Aerodynamic

4.  A separate external supply of air is fed under
pressure between the two surfaces being kept
apart.
 The pressure inside the gap creates the load
carrying properties which are limited only by
the available supply line pressure and material
strength.
 They have found popular use in grinding,
machining and micro positioning applications
where full performance at zero speed and the
absence of friction is essential.

5.  Aerodynamic or self-acting bearings, the air film
is created by the relative motion of two mating
surfaces separated by a small distance.
 As the speed increases, a velocity induced
pressure gradient is formed across the clearance.
The increased pressure between the surfaces
creates the load carrying effect.
 The load capacity is dependent on the relative
speed at which the surface moves and therefore at
zero speed, the bearing supports no load.

6.  Deflated :
In the deflated stage, the air bearing , it is resting on the
floor with most of the weight being supported by the center load pad.
 Inflated :
The second image shows the air bearing in an inflated form
after it has formed a seal with the floor surface. At this stage, the load
has not been engaged to float away from the floor.

7.  Load Lifted On Air :
The above image shows the air bearing
after it has engaged and floated the load. Compressed air will
then start to escape from the bearing diaphragm into the area
that is being contained by the floor seal.
 The weight of the load causes the compressed air escaping out
of the air bearing to force downward onto the floor surface thus
causing the load to float away from the floor.

10.  Lifting weights
 Machines for the Image Setting Industry
 Coordinate Measuring Machines
 Testing Equipment
 High Speed Equipment
 Ultra accurate machine tools
 Linear Stages

11.  Greater Precision
 High Speed
 Increased Tool Life
 Improved Surface Finish
 Long Bearing Life
 Low Thermal Growth
 Lack of Maintenance
 Large Load Capacity
 Reduced Vibration

12.  High geometry accuracy during manufacturing.
 High cost.
 Need to have clean working environment.

13.  By stating the above points air bearings will soon
replace the conventional bearings in high speed, low
loading applications because of their excellence in
overcoming the friction related problems.
 As the technology is non-stationary, it is sure that the
shortcomings of air bearings will soon be removed and
the air bearings will be applicable in many more
applications and fulfill the demands of machine
designers.

14.  Licht L, Elrod H. A study of the stability of
externally pressurized gas bearings.
 Bassani R, Ciulli E, Forte P. Pneumatic
stability of the integral aerostatic
bearing:comparison with other types of
bearing.
 Application of Air Bearings to an
Electrodynamic Vibration Standard T. Dimoff
and B. F. Payne