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:
Mar. 10, 1998
Filed:
Dec. 19, 1996
Paul Gonnard, Villeurbanne, FR;
Lionel Petit, Lyon, FR;
Figest BV, Leiden, NL;
Abstract
Traveling-wave piezoelectric motor comprising at least one stator (1), two groups of piezoelectric elements consisting of ceramic rods (5) polarized independently of one another, arranged perpendicularly to the stator and excited by an alternating current with a phase shift of .pi./2 between the groups so as to generate a deformation in the form of a traveling wave on the surface of the stator (1), and at least one rotor (2, 3) in the form of a disk. The stator is in the form of a wheel consisting of a peripheral annulus over which the piezoelectric elements are distributed, of a central hub and of linking arms intended to transmit an axial pressure exerted on the hub to the annulus. It is thus possible to compress the rods with a much greater force than that applied to the rotor. This prestress has the effect of limiting the spread in the resonant frequencies.