Abstract: Machine tool for machining of a rotating workpiece, comprising a tool drive, a workpiece drive for rotatably driving the workpiece, a tool rotationally driven by the tool drive in synchronization with the workpiece for producing a toothing on the workpiece, rotation transmitters for determining rotational condition of the tool and the workpiece, respectively, an electronic control for keeping the workpiece drive and the tool drive in synchronization by respectively associated ones of the rotation transmitters. A positioning motor is associated with one of the two drives for influencing the position of the phases of the two drives, and a sensor element provided in association with one of the two rotation transmitters is rotatably adjustable with respect to a stator of a corresponding one of the drives.

Abstract: The invention concerns a machine tool for the bovelling of a gear, in which two topfaces are simultaneously milled, with a rotationally driven workpiece carrier and two rotationally driven mounting spindles (13) which can be placed on the workpiece in an axial direction and whose rotationally driven angle of orientation towards the workpiece axis is adjustable in order to receive a milling machine at any one time, especially face milling cutters or single-tooth fly cutters. The workpiece is alternatively clocked or rotationally driven in a continuous manner and the mounting spindles (13) can be moved on a forwards or backwards axis in synchronization with the workpiece cycle or in synchronization with the continuous rotation of the workpiece on a fixed axis. The workpiece is moved forwards in the direction of the axis and each mounting spindle (13) is provided with a slide (12), which can be moved by an axial displacement drive (15).