Moulinex Sa

Somfy

Crouzet Automatismes

Crouzet Automatismes S.a.

Bertrand Nogarede

Bernard J Grehant

Lionel Petit

Eric Piecourt

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).

Supply circuit for a traveling-wave piezo-electric motor

Circuit for supplying a piezo-electric motor

A rotating machine comprises a stator that is excited to vibrate to generate progressive surface waves at a frequency within a resonance frequency range of a predetermined rank. The rotor is designed so that the vibrations in the stator generate vibrations of the same frequency and of lower magnitude. A vibration sensor is mounted on the rotor to provide a signal. The difference in frequency between the excitation frequency of the stator and the vibration frequency detected on the rotor corresponds to the rotation speed of the rotor.

Surface acoustic wave machine

A motor includes two parts that are mobile one with respect to the other and have facing surfaces contacting each other. Progressive surface acoustic waves of the same direction are produced in each facing surface of each part. The relative speed or position of the parts is adjusted by acting on the relative frequency or phase of the progressive waves.

Surface acoustic wave motor

Growing community of inventors

Toulouse, France

Bertrand Nogarede