A device for clamping a workpiece has a receiving head in a housing connected to a rotary drive with a rigid drive connection between a drive motor and the receiving head, radially adjustable clamping jaws connected to a clamping drive externally clamping the workpiece, and linear drives displacing the clamping jaws and forming the clamping drive driven jointly by a gear transmission with a central gear coaxial to the drive shaft of the receiving head by a separate drive motor. The central gear can be driven synchronously with the receiving head in the clamping position of the clamping jaws, and the rotary drive for the central gear comprises a rigid drive connection between its drive motor and the central gear or a superimposed gear comprising two input shafts drive-connected to the drive motor for the rotary drive of the receiving head and to the drive motor for the central gear.

A device for clamping a workpiece has a receiving head in a housing connected to a rotary drive with a rigid drive connection between a drive motor and the receiving head, radially adjustable clamping jaws connected to a clamping drive externally clamping the workpiece, and linear drives displacing the clamping jaws and forming the clamping drive driven jointly by a gear transmission with a central gear coaxial to the drive shaft of the receiving head by a separate drive motor. The central gear can be driven synchronously with the receiving head in the clamping position of the clamping jaws, and the rotary drive for the central gear comprises a rigid drive connection between its drive motor and the central gear or a superimposed gear comprising two input shafts drive-connected to the drive motor for the rotary drive of the receiving head and to the drive motor for the central gear.

Provided is a clamp device having a simple configuration comprising a plurality of detection valves for detecting an operation state. A piston rod is provided within a housing so as to be capable of moving vertically. A first detection valve is provided to a first flow path through which flows compressed air for detection, the first flow path being formed within the housing. A valve member of the first detection valve is manipulated by manipulation part provided so as to project radially from the outer peripheral wall of the piston rod. A second detection valve is provided to a second flow path through which flows compressed air for detection, the second flow path being formed within the housing. A valve surface of the second detection valve formed on the manipulation part is capable of engaging with a valve seat formed within the housing.