Balancing of a high speed rotor in aerodynamic bearings

For applications in laser display technology, a polygonal line scanning device based on aerodynamic hemispherical bearings is being developed in our laboratory. The rotor of the device requires precise balancing for reliable performance at rational speeds > 60 000 rpm. We estimate the necessary balancing quality from basic considerations and describe, how balancing is being performed. Sufficiently precise balancing for operation at target speed is shown to be achieved within the rigid rotor approximation. Stability is satisfactory according to preliminary results, obtained with a dummy system. To further extend life time, tests have been carried out with compensating polygon related unbalances on the part itself. The results fully confirm our expectations. This shows, that the design concept is sound and that the intended the quality will be realised with the final system.