A machine tool includes a bed, and a table that is provided on the bed and movable in a Z-axis direction. The table includes a workpiece holder, a table base including a first support portion and a second support portion for turnably supporting the workpiece holder at positions spaced from each other in an X-axis direction, the workpiece holder being mounted on the table base, and a turning device that is provided in the first support portion, and turns the workpiece holder around a turning center axis extending in the X-axis direction. The machine tool further includes a first feeding device and a second feeding device that are provided on the bed and are connected to the first support portion and the second support portion respectively to drive the table in the Z-axis direction.

A high-speed nut rotation feed ball screw device includes a ball screw, a ball screw nut, a bearing unit, and a driving unit. The ball screw is fixed on a machine tool via a ball screw seat. The bearing unit includes an inner bearing fixing sleeve, an outer bearing fixing sleeve, and a bearing assembly. One end of the inner bearing fixing sleeve is fixedly connected to one end of the ball screw nut, and another end is fixedly connected to the driving unit. The ball screw nut is arranged on the ball screw. The driving unit includes a first pulley, a second pulley, a synchronous belt, and a driving motor. The first pulley is connected to the driving motor. The second pulley is sleeved on the ball screw and is connected to the inner bearing fixing sleeve. The first and second pulleys are connected via the synchronous belt.