Device for clamping a rotatably mounted shaft element, in particular for use on a machine tool, and axis structure of a machine tool

A device for clamping a rotatably mounted shaft element, comprising:

• a housing element having an annular housing portion, wherein the rotatably mounted shaft element can be arranged extending in axial direction through an inner region of the annular housing portion;
• an elastically deformable annular clamping ring element arranged in the annular housing portion of the housing element, wherein the clamping ring element comprises a cross-sectional profile, comprising a first profile portion which extends radially inward and protrudes radially toward the rotatably mounted shaft element through an annular circumferential opening of the annular housing portion, and at least a second profile portion which extends transversely to the first profile portion;
• a pressure chamber which is formed in the annular housing portion of the housing element and comprises at least one pressure chamber portion arranged radially on the inner side adjacently to the at least one second profile portion of the clamping ring element;
• wherein the rotatably mounted shaft element in a rest state of the clamping ring element can be clamped by frictional connection with the first profile portion of the clamping ring element protruding towards the shaft element, and wherein the frictional connection between the shaft element and the first profile portion for releasing the clamping of the shaft element is releasable by the clamping ring element being elastically deformable radially outward by application of pneumatic or hydraulic pressure of the pressure chamber.