A device for clamping a rotatably mounted shaft element including: a housing element having an annular housing portion wherein the shaft extends in the axial direction; an elastically deformable annular clamping ring element arranged in the annular housing portion, wherein the clamping ring has a cross-sectional profile with a first profile portion, extending radially inward and protrudes radially through an annular circumferential opening; and a pressure chamber formed in the annular housing has at least one pressure chamber portion arranged radially on the inner side adjacently to at least one second profile portion of the clamping ring; wherein the rotatably mounted shaft in a rest state clamped by frictional engagement with the first profile of the clamping ring protruding toward the shaft, and wherein the frictional engagement between the shaft and the first profile is releasable, the clamping ring is elastically deformable radially outward by pneumatic or hydraulic pressure chamber.