Abstract: The invention relates to an ultrasonic motor comprising a plate-shaped piezoelectric ultrasonic actuator (2) and a of friction element (5) arranged on a side surface thereof, wherein the connection line (V) through the friction point and the focal point (S) of the ultrasonic actuator defines an operating direction, and a perpendicular plane intersecting the ultrasonic actuator defines an operating plane (W). A holder (6) has two force inlet sections (7) in order to move the holder and thereby the ultrasonic actuator in a direction parallel to the operating direction, and to press same against an element to be driven. The force inlet sections, preferably based on permanent magnets (8, 9) are each arranged in the operating plane and laterally next to and at a distance from the the ultrasonic actuator, and the intersection point (SP) of the connection line (V) with the operating plane (W) either coincides with the focal point (S) or lies between the focal point and the side surface having the friction element.

Abstract: A method and device are disclosed for actuating a piezoelectric motor by two driving electrodes by applying periodic control voltages to the driving electrodes. A simplified closed-loop control of the piezoelectric motor is realized by reducing the static friction of a friction contact between a friction element of the piezo-electric motor and an output element to be driven by the friction element without a propulsion of the output element at the same time. In exemplary embodiments, the periodic control voltages are applied with a phase shift to the driving electrodes in a first step of the method, and in a second step of the method, the amplitude ratio of the periodic control voltages is changed with respect to the first step.

Abstract: The invention relates to an ultrasonic motor comprising a plate-shaped piezoelectric ultrasonic actuator (2) and a of friction element (5) arranged on a side surface thereof, wherein the connection line (V) through the friction point and the focal point (S) of the ultrasonic actuator defines an operating direction, and a perpendicular plane intersecting the ultrasonic actuator defines an operating plane (W). A holder (6) has two force inlet sections (7) in order to move the holder and thereby the ultrasonic actuator in a direction parallel to the operating direction, and to press same against an element to be driven. The force inlet sections, preferably based on permanent magnets (8, 9) are each arranged in the operating plane and laterally next to and at a distance from the the ultrasonic actuator, and the intersection point (SP) of the connection line (V) with the operating plane (W) either coincides with the focal point (S) or lies between the focal point and the side surface having the friction element.

Abstract: A method and device are disclosed for actuating a piezoelectric motor by two driving electrodes by applying periodic control voltages to the driving electrodes. A simplified closed-loop control of the piezoelectric motor is realized by reducing the static friction of a friction contact between a friction element of the piezo-electric motor and an output element to be driven by the friction element without a propulsion of the output element at the same time. In exemplary embodiments, the periodic control voltages are applied with a phase shift to the driving electrodes in a first step of the method, and in a second step of the method, the amplitude ratio of the periodic control voltages is changed with respect to the first step.