Machine tool and workpiece chuck

A workpiece chuck for a tool spindle of a machine tool rotatable about a spindle axis, the workpiece being clampable in said chuck with a variably adjustable eccentricity in relation to the spindle axis,

• the workpiece chuck having a chuck housing, a collet actuation and a collet support arranged in the chuck housing, said collet support having a collet held in it,
• said collet being adapted to be brought into concentric or eccentric adjustable positions relative to the spindle axis as a result of movement of the collet support relative to the chuck housing,
• a receiving means being provided on the collet support for the adjustment of the adjustable positions of the collet,
• said receiving means being adapted to be brought into operative connection with an adjusting element of the machine tool, and
• in the operative connection between the adjusting element and collet support, relative movement between the collet support and the chuck housing being achievable for changing the adjustable position.

A machine tool for the turning of workpieces with eccentric sections, comprising:

• a tool support movable in a direction of at least one axis,
• a workpiece spindle drivable for rotation about a spindle axis, said workpiece spindle comprising a workpiece chuck adapted to clamp a workpiece with a variably adjustable eccentricity in relation to the spindle axis,
• the workpiece chuck having a chuck housing, a collet actuation and a collet support arranged in the chuck housing and having a collet held therein,
• said collet being adapted to be brought into concentric or eccentric adjustable positions relative to the spindle axis as a result of movement of the collet support relative to the chuck housing,
• said machine tool having at least one machining axis out of at least one of a turret axis and a rotary axis of the workpiece chuck controlled by a machine control,
• an adjusting element on the machine tool, said element being moveable towards the workpiece chuck for the adjustment of a respective adjustable position of the collet, and being adapted to be brought into operative connection with a receiving means connected to the collet support, and
• in the operative connection between the adjusting element and the collet support, the relative movement between the collet support and the chuck housing being controllable for changing the adjustable position via the machine control by controlling the at least one machining axis out of at least one of a turret axis and a rotary axis of the workpiece chuck.