A comparative study of bearing designs and operational environments for harmonic side-drive micromotors

The authors report the development of flange bearing harmonic side-drive (referred to as wobble) micromotors and the results from a comparative study of the operation of flange and center-pin bearing micromotors in different gas environments. Both the flange and center-pin wobble micromotors have been operated with excitation as low as 30 V across 1.5 mu m rotor/stator gaps. In contrast to the center-pin bearing wobble micromotors it was found that the performance of the flange bearing wobble micromotors is not significantly affected by the operational environment. A convenient experimental procedure to characterize friction in wobble micromotors has been developed. Additionally, the requisite wobble micromotor dynamic model for extracting the bearing and bushing/flange frictional parameters from the experimental data is discussed.< >