Abstract: A piezoelectric actuator unit includes a piezoactuator and a casting compound enclosing the piezoactuator. The casting compound is disposed in a sleeve that includes a hydrophobic material.

Abstract: A piezoelectric actuator unit includes a piezoactuator and a casting compound enclosing the piezoactuator. The casting compound is disposed in a sleeve that includes a hydrophobic material.

Abstract: A piezoelectric resonator arrangement comprises a mount having at least two mounting elements on a base structure and at least one laminar piezoelectric resonator that is clamped between the mounting elements, of which at least one impinges on the resonator with a force. In order to obtain the oscillation and resonance characteristics in a manner as free as possible of influence from the mounting or, respectively, contacting, and over a large temperature range in order also to minimize the temperature-caused hysteresis of the resonance characteristics, the mounting elements abut immediately and directly on the resonator and fix this resonator in the arrangement without the use of adhesive, and the points of contact of the mounting elements with the resonator are located essentially in one plane that lies essentially parallel to the plane of the resonator, and, in addition, the mounting and contacting forces exerted by the mounting elements lie essentially parallel to the plane of the resonator.