Abstract: A traveling wave piezoelectric motor having essentially a stator (1) in the form of an annular plate PLANE, the stator connected to two groups of cylindrical polarized ceramic piezoelectric elements (2, 3, 4) and excited by an alternating current with a phase shift of 90 degrees between the groups so as to generate a deformation in the form of a traveling wave at the surface of the stator, and of a rotor in the form of a disk. The piezoelectric elements are connected to the stator by the intermediary of an auxiliary coupling piece (5, 6, 7) in the form of a truncated segment and in permanent contact with the stator by their small-section extremity.

Abstract: Supply circuit for a piezo-electric motor comprising a rotor driven, by friction, by a stator energized by at least two piezo-electric elements (P1, P2) supplied respectively with two alternating voltages (Vp, Va) of like amplitude and phase-shifted by approximately 90.degree. by means of a single source and of a means intended for generating the two phase-shifted voltages. This means consists of a capacitor (C), in series with one of the piezo-electric elements (P2), whose value is chosen so that for a given frequency of the voltage of the source (S), substantially the same voltages and a phase-shift of 90.degree. is obtained. The voltage of the source is advantageously controlled, in frequency, by a processing logic unit (PLU).

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.