Measuring central stiffness of an air bearing spindle

摘要

We describe a test for stiffness and load capacity for the radial bearings of an air bearing spindle. A feature of interest is the ability to measure "central stiffness", which is important for precision machining because it is needed to resist drive influence, unbalance, and tool forces. Central stiffness also comes into play on the final light cut, especially with interrupted surfaces. We define central stiffness as the ability to respond to small increases in force, particularly when the rotor is centered.