Patent ID: 10236797

Abstract:
The invention relates to an ultrasonic motor, comprising a piezoelectric ultrasonic actuator (1) having four friction elements (4) disposed thereon, a friction surface (6) which is in frictional contact with the friction elements, and an electrical excitation device (16), wherein the ultrasonic actuator is in the shape of a ring or hollow cylinder, having an inner circumferential surface (14), an outer circumferential surface (12) and two planar end surfaces (5) connecting the inner and the outer circumferential surfaces. The four friction elements are disposed on one of the end surfaces of the ultrasonic actuator so as to be spaced equidistantly with respect to the circumferential direction, such that in each case two of the friction elements lie diametrically opposite, and the ultrasonic actuator comprises twelve identical circumferential sections (10), each of which has a generator for an acoustic standing wave to be formed in the ultrasonic actuator and the deformations of the ultrasonic actuator caused by the standing wave lead to deflections of the friction elements on a movement path inclined with respect to the end surface and/or a movement path substantially perpendicular to the end surface. Each generator has at least one excitation electrode (11), at least one general electrode (13) or a section of a general electrode and a layer of piezoceramic (15) disposed between the excitation electrode and the general electrode or the section of the general electrode.