The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 14, 2002
Filed:
Oct. 03, 2000
Bernard Grehant, Nancy-sur-Cluses, FR;
Metabole Developpement et Conseil, Cluses, FR;
Abstract
A traveling wave ultrasonic motor includes a ring-shaped stator ( ) and two groups of electromechanical transducers ( to ). Each group comprises a pair of diametrically opposed longitudinal transducers, polarized in opposite directions, disposed perpendicularly to the stator ( ). The transducers are in permanent contact with the stator ( ) and excited by an alternating current with a &pgr;/2 phase shift between the groups so as to produce a traveling wave-like deformation on the surface of the stator ( ). The motor comprises at least one rotor ( ) held elastically in contact with the stator ( ) for the rotational driving thereof by the traveling wave produced on the stator. The stator is in contact with the rotor only via two or four equal and diametrically opposed segments ( ) whose aggregate span is at most equal to a wavelength of the traveling wave produced in the stator.