A cutting apparatus adapted for use in a machine tool. The cutting apparatus includes a mounting frame. A cutting unit is mounted rotatably in the mounting frame. A locking unit is connected to the mounting frame and the cutting unit, for restraining or permitting relative movement between the mounting frame and the cutting unit. A driving unit drives rotation of the cutting unit. A control unit controls the driving unit to drive rotation of the rotating shaft upon detecting that the relative movement between the mounting frame and the cutting unit is permitted. The control unit shuts off the driving unit upon detecting that the relative movement between the mounting frame and the cutting unit is restrained.

A rotary shaft locking device includes a rotary shaft, a first angular contact ball bearing, a support, and an actuator. The rotary shaft is rotatable about a first axis and has a first contact surface. The first angular contact ball bearing includes an inner ring connected to the rotary shaft, an outer ring, and a plurality of balls disposed between the inner ring and the outer ring. The support has a second contact surface and rotatably supports the rotary shaft via the first angular contact ball bearing. The actuator is configured to move the rotary shaft and the inner ring with respect to the support and the outer ring in a first direction parallel to the first axis so that the first contact surface contacts the second contact surface to prohibit the rotary shaft from rotating and so that precompression that acts on the plurality of balls is reduced.

A turret device having a configuration for obtaining required processing accuracy, includes: an indexing motor configured to pivotally index a turret tool; a turret shaft configured to transmit a rotation of the indexing motor; and a turret head coupled to the turret shaft on which multiple turret tools are mounted on a circumference, wherein the turret head includes a diaphragm-type base member coupled to the turret shaft, an inner diameter side of the base member is coupled to the turret shaft, and an outer diameter side of the base member is rotationally supported by a bearing fixed to a main body member of a turret.

The present invention relates to a method for operating a pivot drive, in particular a rotary indexing table, comprising an output element that can be driven to make a rotational movement, in particular a turntable, and an electrically actuatable braking device for braking and/or fixing the output element, wherein a time development of at least one characteristic parameter of the energization of the braking device is determined during an actuation of the braking device and a state of the braking device is determined on the basis of an analysis of the time development of the characteristic parameter. A corresponding pivot drive is further described.