MICROMACHINED TRAVELING-WAVE MOTORS - 3-DIMENSIONAL MECHANICAL OPTIMIZATION AND MINIATURIZATION LIMITS EVALUATION

Citation
P. Minotti et al., MICROMACHINED TRAVELING-WAVE MOTORS - 3-DIMENSIONAL MECHANICAL OPTIMIZATION AND MINIATURIZATION LIMITS EVALUATION, JPN J A P 1, 36(11), 1997, pp. 7009-7018
Citations number
16
Language
INGLESE
art.tipo
Article
Volume
36
Issue
11
Year of publication
1997
Pages
7009 - 7018
Database
ISI
SICI code
0021-4922(1997)36:11<7009:MTM-3M>2.0.ZU;2-L
Abstract
This paper concerns a physical limits evaluation with respect to the m iniaturization of traveling wave type ultrasonic motors (TWUM) down to the millimeter scale. According to present knowledge in research dedi cated to centimeter scale TWUM, two different prototypes, whose extern al diameters are phi 5 mm and phi 2 mm, have previously been designed through numerical calculations, and fabricated using watch making tech nologies. An experimental characterization has been carried out in ord er to identify the main physical and technological limitations specifi c to millimeter scale traveling wave motors. The very first numerical results presented in this paper show important outcomes related to the miniaturization of TWUM. In particular, the Limits of current mechani cal assumptions such as those related to the two-dimensional mechanica l behavior of the stator/rotor interface and also to the rotor's rigid ity are clearly shown by a three dimensional finite element calculatio n. New design rules are thus given in order to allow the mechanical ar chitecture of TWUM to be optimized. The corresponding results indicate that powerful torque/speed characteristics can be expected, and there fore show the adequacy of traveling wave ultrasonic motors for direct- drive actuation down to the millimeter scale.