A device for clamping a workpiece comprises a chuck body and a drive fastened thereto, and at least one clamping jaw, which is coupled to the drive in a driveable arrangement either directly or via intermediate elements and which is or are held movably in or on the chuck body in the direction of the workpiece. This is achieved by providing a free space between the chuck body and a clamping jaw carrier accommodating the clamping jaw, in that an elastically deformable sleeve is inserted in the free space, which sleeve rests on the outside of the chuck body at two positions spaced apart from one another, and in that a pressure chamber is created between the chuck body, the sleeve, and the two support positions into which a medium can be filled, whereby to bulge the latter in the direction of the clamping jaw carrier between the support positions.

A device (1) for clamping a workpiece (2) to be machined, in particular a chuck or vice, the device comprising: (i) a chuck body (3) and a drive (5) fastened thereto, and (ii) at least one clamping jaw (6), which is coupled to the drive (5) in a driveable arrangement either directly or via intermediate elements (7) and which is or are held movably in or on the chuck body (3) in the direction of the workpiece (2). On the one hand, reliable and centric clamping of the workpiece (2) in a predetermined position is achieved and, on the other hand, the mounting of the clamping jaw carrier (9) on the chuck body (3) is free of backlash in the clamped condition in order to prevent any possibility of movement of the workpiece (2) relative to the chuck body (3). This is achieved by providing a free space (11) between the chuck body (3) and a clamping jaw carrier (9) accommodating the respective clamping jaw (6), in that an elastically deformable sleeve (12) is inserted in the free space (11), which sleeve (12) rests on the outside (8) of the chuck body (3) at two positions (21) spaced apart from one another, and in that a pressure chamber (14) is created between the chuck body (3), the sleeve (12) and the two support positions (21) thereof, into which pressure chamber (14) a medium (16) can be filled, by means of which a pressure force directed outwards acts on the wall (W2) of the sleeve (12) and bulges the latter in the direction of the clamping jaw carrier (9) between the support positions (21).