Design of a Linear Ultrasonic Piezoelectric Motor Design of a Linear Ultrasonic Piezoelectric Motor
A prototype frame was built out of tool steel and run against an oxide ceramic plate. The USM prototype?s piezoelectric elements did not provide the expected displacements in the motor frame as determined by the FEM. The discrepancy was determined to be caused manufacturing errors. Soft glue layers were thicker than expected on each side of the piezoelectric elements causing a large amount of compliance inline with the piezoelectric motion. An additional unexpected layer of glue between the end cap and frame increased the compliance inline with the piezoelectric elements even more. It was also determined that even if the motor had been assembled properly that Hertzian displacement would have caused a 1/3 decrease in piezoelectric motion. The prototype frame?s steady state displacements were approximately 20% of the expected output from the FEM models. The motor was still able to achieve a maximum speed of 55.6 mm/s and a push force of 0.348 N at a preload of 6 N. It is expected that a motor assembly correctly dimensioned and manufactured and designed to minimize Hertzian displacement would result in a significantly better performing prototype.
School:Brigham Young University
School Location:USA - Utah
Source Type:Master's Thesis
Keywords:ultrasonic motor usm piezoelectric actuator
Date of Publication:07/06/2006