Abstract: The invention relates to a method for the manufacture of piezoelectric multilayer actuator in which thin layers of a piezoceramic material, called “green leaves” on which at least one internal electrode is applied, are stacked to form a block such that the internal electrodes are guided in alternation to oppositely lying surfaces of the actuator, where they become bound together by an external electrode, the actuator compact being sintered and subjected to abrasive shaping, and then the base metallization is applied for the external electrode.

Abstract: In external electrodes on piezoceramic multi-layer actuators, high tensile stresses act during operation on the insulating region below the base metallic coating. Problems are caused by the linking of the electrode with a conductive connection, via which the electric voltage is to be supplied. The soldering or welding process reinforces the external electrode, which thus loses elasticity at the soldering or welding point. During operation, mechanical shear stresses then occur beneath said soldering or welding points, as the electrode region lying above no longer expands. After several million operating cycles, this causes the external electrode together with the base metallic coating to become detached, thus leading to the failure of the component.

Abstract: The invention relates to a monolithic multilayer actuator comprising a sintered stack of thin films, made from piezo-ceramic with inlaid metallic inner electrodes which extend from the stack on alternate sides and are electrically wired in parallel with external electrodes (3, 4) and are provided with connector wires (5). According to the invention, the actuator may be supplied with nominal voltage over a long period of time, without a change in the properties thereof, whereby the multilayer actuator (1) is sealed within a metallic or ceramic housing (8, 11, 16), the connector wires (5) are integral parts of the housing base (11) and the housing (8, 11, 16) is filled with a water-absorbing medium (14) and a water-transporting, electrically-insulating medium (15).

Abstract: The invention relates to a monolithic multilayer actuator comprising a sintered stack of thin films, made from piezo-ceramic with inlaid metalic inner electrodes which extend from the stack on alternate sides and are electrically wired in parallel with external electrodes (3, 4) and are provided with connector wires (5). According to the invention, the actuator may be supplied with nominal voltage over a long period of time, without a change in the properties thereof, whereby the multilayer actuator (1) is sealed within a metallic or ceramic housing (8, 11, 16), the connector wires (5) are integral parts of the housing base (11) and the housing (8, 11, 16) is filled with a water-absorbing medium (14) and a water-transporting, electrically-insulating medium (15).

Abstract: The invention relates to a method for the manufacture of piezoelectric multilayer actors in which thin layers of a piezoceramic material, called “green leaves” on which at least one internal electrode is applied, are stacked to form a block such that the internal electrodes are guided in alternation to oppositely lying surfaces of the actor, where they become bound together by an external electrode, the actor compact being sintered and subjected to abrasive shaping, and then the base metallization is applied for the external electrode.

Abstract: A monolithic multi-layer actuator includes a sintered stack of thin films of piezoceramic material with metallic internal electrodes which lead out of the stack (2) in alternate directions and are connected electrically in parallel by way of external electrodes, with the external electrodes on the contact sides of the stack consisting of an applied basic metallisation and being connected to electrical connection elements preferably by way of soldering. In order to avoid failures of the actuator during dynamic loads it is suggested that an electroconductive electrode which is structured to be three-dimensional in structure be arranged between the basic metal lining and the connection elements, which electrode is connected to the basic metallisation by way of partial contact points and is constructed to be expandable between the contact points.