Abstract: The invention relates to a hydraulic expansion chuck comprising a main body (1) that extends along a rotational or longitudinal central axis (2) and is composed of a shaft part (20), for directly or indirectly coupling the hydraulic expansion chuck to a module of a modular tool system or to a machine spindle, and a clamping part (30), joined to the shaft part in a rotationally and axially fixed manner for receiving and clamping a shank tool. The shaft part comprises a receiving socket which extends towards the clamping part and has a central socket-opening in which a connection pin (31) of the clamping part, which pin extends towards the shaft part, is form-fittingly received. According to the invention, the clamping part comprises a stop which is radially offset from the connection pin and axially strikes the receiving socket.

Abstract: Spindle units are provided for machining devices, in particular for a lathing spindle unit, center drive assembly or milling spindle unit. The spindle unit comprises: a spindle shaft rotatably supported in a housing, a chucking device disposed at the spindle shaft for clamping a workpiece or a tool, a motor drive connected to the spindle shaft for driving the spindle shaft around a drive axis, a clamping device for clamping the spindle shaft at a freely selectable angular position around the drive axis, wherein the clamping device is disposed between the spindle shaft and a stationary part of the spindle unit, and an actuating device for actuating and/or releasing the clamping device. The clamping device can be axially actuated in the direction of the drive axis such that an axial or substantial axial clamping force acts in the direction of the drive axis with the clamping device being actuated.

Abstract: Spindle units are provided for machining devices, in particular for a lathing spindle unit, center drive assembly or milling spindle unit. The spindle unit comprises: a spindle shaft rotatably supported in a housing, a chucking device disposed at the spindle shaft for clamping a workpiece or a tool, a motor drive connected to the spindle shaft for driving the spindle shaft around a drive axis, a clamping device for clamping the spindle shaft at a freely selectable angular position around the drive axis, wherein the clamping device is disposed between the spindle shaft and a stationary part of the spindle unit, and an actuating device for actuating and/or releasing the clamping device. The clamping device can be axially actuated in the direction of the drive axis such that an axial or substantial axial clamping force acts in the direction of the drive axis with the clamping device being actuated.