Patent ID: 7238082

Claim:
A workpiece headstock for a machine tool, especially for a grinding machine, with a spindle ( 6 ); with a clamping device ( 7 ), which is connected to the spindle ( 6 ) and which is used to clamp a workpiece ( 8 ) to be machined; and with a spindle drive ( 9 ), where, a loosenable alignment interface ( 14 ) is provided between two sections of the spindle ( 6 ), between the spindle ( 6 ) and the clamping device ( 7 ), or between two sections of the clamping device ( 7 ); where, after the alignment interface ( 14 ) has been loosened and while the workpiece headstock ( 1 ) otherwise remains stationary, the clamping device ( 7 ) and thus the workpiece ( 8 ) clamped in it can be aligned in a plane perpendicular to the spindle axis ( 15 ), as a result of which any existing offset between the workpiece axis ( 17 ) and the spindle axis ( 15 )—i.e., the eccentricity of the clamped workpiece ( 8 )—can be eliminated; where an adjusting device ( 18 ) is provided for the alignment of the clamping device ( 7 ), the adjusting device ( 18 ) is designed as a unit separate from the clamping device ( 7 ) and from the spindle ( 6 ) and has an actuating drive ( 19 ); in that the clamping device ( 7 ) can be aligned by the motor of the actuating drive ( 19 ); in that a sensor arrangement ( 20 ) is provided, from the measurement values of which the eccentricity of the clamped workpiece ( 8 ) can be determined; in that an alignment control unit ( 21 ) is provided, which is connected on one side to the actuating drive ( 19 ) and on the other side to the sensor arrangement ( 20 ) in a manner suitable for the purpose of control technology; and in that to align the clamping device ( 7 ), the alignment control unit ( 21 ) operates the actuating drive ( 19 ) as a function of the measurement values provided by the sensor arrangement ( 20 ) and thus cooperates with the actuating drive ( 19 ) and the sensor arrangement ( 20 ) to form a closed-loop control circuit.