Abstract: A mobile, self-propelling crushing machine includes a structure essentially consisting of two beams, on which a central frame is welded. The central frame houses a rotor which is supported on a frame, which, in one form, is lowered by hydraulic cylinders fixed to the frame. In another form, the frame is lowered by four mechanical jacks being driven by a single hydraulic motor. Thus, the penetration of the rotor into the soil to be treated does not depend only on its own weight, but especially on the action of the just-mentioned hydraulic cylinders or mechanic jacks. The rotor is driven by two hydraulic motors which are opposite to one another and which are self-adjusting so that when a pressure transducer signals a pressure increase to the hydraulic motors of the rotor due to an increased effort, the forward movement speed of the machine, which moves on tracks, decreases as a consequence.