Analysis of Deformation of Air-spindle due to Centrifugal Force.

This paper deals with FEM and experimental investigations of the deformation of precision airspidle in diametrical expansion and axial contraction due to the centrifugal force during spindle rotation. The deformation of spindle rotor is measured with special experimental setup and the results are compared with the FEM analysis. Special precautions are taken in the experiments to realize precision measurement of the order of one-hundredth micro-meter, such as compensation of the thermal deformation of spindle, protection of the sensor probes against exhaust air flow from the air bearing and low-pass filtering of the displacement output. The experiments are carried out in a speed range up to 7200 rpm, and it is clarified that the measured results agree well with the calculation.