Bending apparatus for bending a piezoelectric bending element, a piezoelectric energy converter for converting mechanical energy into electrical energy by means of the bending apparatus and method for converting the mechanical energy into electric energy

There is provided a bending device for bending a piezoelectric bending element, with a workpiece with a support surface having at least a convex curvature, a counter workpiece with a counter-bearing surface with an inverse to the convex curvature of the bearing surface is substantially concave curvature and an apparatus to a such relative against each other comprises moving the workpiece and the counter workpiece, that the convex curvature of the bearing surface in the concavity can be conducted counter-support surface. For energy conversion is the bending element, preferably a circular disk benders, arranged in a space between the bearing surface and the counter-bearing surface, so that there is a bending of the flexure due to the relative against each other moving the workpiece and the counter workpiece. By using a circular disc bender mechanical energy is converted with high efficiency into electric energy. Due to the configuration of the workpieces with their bearing surfaces is provided for overload protection. The invention finds use in self-powered systems for converting mechanical energy into electrical energy.