A device for producing a fluid jet suitable for hygienic requirements in mechanical wound cleaning, including removal of biological tissue, may include a drive casing with a drive and a pump module with a pump casing which can be detachably joined. The drive casing may include a positive-locking element and the pump casing may include a positive-locking counter-element. The positive-locking element may interact with the positive-locking counter-element so that the pump casing is imposed a pivotal motion relative to the drive casing until reaching a final position. In final position the pump casing may be connected to the drive casing and a drive element may be connected to an associated drive counter-element. Drive element and drive counter-element may be arranged eccentric to a pivot axis of the pivotal motion and may be formed so a positive-locking connection arises between the drive element and drive counter-element due to the pivotal motion.