Positioning system for an additive manufacturing system, and additive manufacturing system

An additive manufacturing system, comprising a build-up chamber enclosed by outer panelings of the additive manufacturing system and a positioning system being suited for positioning a print head, wherein the positioning system allows movements in several degrees of freedom and the positioning system is of two-part design, wherein a part of the degrees of freedom is made possible by a first part of the two-part design of the positioning system and a further part of the degrees of freedom is made possible by a second part of the two-part design of the positioning system, wherein the first part of the positioning system is arranged so as to be thermally decoupled from the second part of the positioning system by at least one first heat reflector, wherein the first part of the positioning system comprises one or more linear guides housed in the build-up chamber and the second part of the positioning system comprises at least one recirculating ball screw positioned outside the build-up chamber, wherein a drive system of the positioning system is located outside the build-up chamber, and wherein the additive manufacturing system includes a rod or bar that is coupled to the one or more linear guides and the at least one recirculating ball screw, and the rod or bar extends through a bottom element below the build-up chamber.