In order to enable the production of the motor shaft to be simplified in the case of a high-pressure cleaning device comprising a piston pump, the pistons of which are driven by a motor via a wobble plate non-rotatably connected to the motor shaft of the motor, it is suggested that the wobble plate be non-rotatably connected by means of form locking to a coupling element consisting of plastic, this coupling element being attached at its end face to the motor shaft circular in cross section and being tensioned against the end face of the motor shaft by a tension rod held in the motor shaft, thereby forming a friction contact.