Piezoelectric adjustment apparatus

1. A piezoelectric adjustment apparatus,

having a piezoelectric stack which comprises a plurality of layers of piezoelectric material arranged in a stacked manner and each provided with electrodes;

having a lever mechanically connected to the piezoelectric stack for converting a drive movement of the stack into an adjustment movement of an adjustment element provided at the lever, and

having a cooling device for dissipating heat from the piezoelectric stack,

wherein the piezoelectric stack is divided into at least two part stacks arranged next to one another and provided with respective associated electrodes, said part stacks separated from one another by an intermediate space,

wherein the cooling device is arranged at least partly in the intermediate space; and/or wherein fluid present in the intermediate space forms a part of the cooling device, and

wherein the cooling device comprises at least one cooling body of a thermally conductive material arranged at least partly in the intermediate space,

the adjustment apparatus further comprising at least one of a base cooling rib extending from a base and projecting into the intermediate space and a lever cooling rib extending from the lever and projecting into the intermediate space.

2. The adjustment apparatus in accordance with claim 1 ,

wherein the cooling device comprises a layer of thermally conductive material via which layer at least one outer surface of the piezoelectric stack is in contact with a wall section of a housing of the adjustment apparatus.

3. The adjustment apparatus in accordance with claim 2 ,

wherein the outer surface is a side surface.

4. The adjustment apparatus in accordance with claim 1 ,

wherein the piezoelectric stack is divided into exactly two part stacks arranged next to one another.

5. The adjustment apparatus in accordance with claim 1 ,

wherein the piezoelectric stack is divided into part stacks along a division plane extending in parallel with the stack direction.

6. The adjustment apparatus in accordance with claim 5 ,

wherein the piezoelectric stack is divided into part stacks of identical size.

7. The adjustment apparatus in accordance with claim 1 ,

wherein the cooling device comprises a thermally conductive material with which free spaces are filled which are present in the intermediate space between the surfaces of the part stacks.

8. The adjustment apparatus in accordance with claim 1 ,

wherein the piezoelectric stack is clamped by means of a clamping element between a base common to all part stacks and a counter base common to all part stacks, wherein the clamping element extends through the intermediate space in parallel with the stacking direction.

9. The adjustment apparatus in accordance with claim 8 ,

wherein the clamping element comprises a shaft section with a flattened cross-section provided for arrangement in the intermediate space.