Valve actuator for actuating a gas exchange valve of an internal combustion engine

A valve actuator for operating a gas exchange valve of an internal combustion engine, comprising:

• a valve stem;
• a conical clamping sleeve;
• a sleeve-shaped positioning piston connected to the valve stem;
• at least two shell-shaped wedge pieces, which enclose a stem end of the valve stem, and whose radially outer peripheral surfaces have a conical segment which tapers off with increasing distance from the gas exchange valve and which is at least partially surrounded by the conical clamping sleeve having a mating conical inner surface and is connected to the positioning piston;
• and
• a threaded bolt, the wedge pieces being axially form-fittingly and rotatably connected to the threaded bolt, the threaded bolt having at least one threaded segment via which the wedge pieces and the conical clamping sleeve are axially attachable to one another.