A rotary table device includes: a case; a spindle having an axis hole that is provided rotatably in the case and extends through along an axis direction of a center portion; a rotary joint having a rotary shaft attached non-rotatably to the axis hole of the spindle; and a clamp mechanism arranged in a rear end side of the case and having a component attached non-rotatably to the spindle, the rotary shaft having an attachment flange unit with the spindle in a front end portion, the rotary shaft inserted to the axis hole from the front end side of the spindle to be attached to the spindle by the attachment flange unit, a rear end portion of the rotary shaft projecting from a rear end surface of the spindle, the component of the clamp mechanism mounted to a rear end portion of the rotary shaft projecting from the rear end surface of the spindle from a rear end side, and contacting with and externally fit to an outer circumferential surface of the rear end portion.

A machine tool is equipped with a rotary table, and a clamp mechanism which clamps the rotary table in a manner so that the rotary table does not rotate. A clamping operation by the clamp mechanism is started after a standby time has elapsed from completion of indexing of the rotary table. The machine tool further includes a positional deviation calculating unit adapted to calculate a positional deviation of the rotary table when the clamping operation by the clamp mechanism is completed, and a standby time changing unit adapted to shorten the standby time in the case that an absolute value of the positional deviation is less than a threshold value, and to lengthen the standby time in the case that the absolute value of the positional deviation is greater than the threshold value.

The invention relates to a rotary-table bearing assembly, including: a rotary-table bearing, which has an inner ring, an outer ring, and rolling elements arranged in one or more rows, which roll on the inner ring and on the outer ring; and in each case an assembly component having a clamping segment, to which assembly components the outer ring and the inner ring are connected. According to the invention, the clamping segment of at least one assembly component is designed radially elastic on the assembly component, and/or the outer ring and/or the inner ring has a radially elastic connecting segment, by which the particular ring is connected to the assembly component.

A rotary table according to the exemplary embodiment of the present disclosure includes a piston 70 having a first tapered portion 72, and a clamp 80 having a second tapered portion 82. When the first tapered portion 72 comes into close contact with the second tapered portion 82 by a movement of the piston 70, a pallet base 30 is fixed to a table base 10, and thus the pallet base 30 is rotated, thereby maintaining a preset posture.

The present invention provides a lathe that is provided with an eccentricity adjustment mechanism that makes it possible for electrical components that are readily affected by the environment to be eliminated from the turntable; for slip rings in particular, which exhibit problems in terms of the durability of signal transmission during high-speed rotation, to be eliminated as well, and for safe and stable adjustment of workpiece eccentricity to be easily achieved. A lathe provided with an eccentricity adjustment mechanism, in which a linear motion guide unit (6) is provided in an inclined state in an engaging part of the center part of a turntable (1) and an axial-direction-movement part (5A) of a center shaft (5); and, due to the center shaft (5) being moved, the turntable (1) moves in the radial direction by the radial pressing force generated by the linear motion guide unit (6) being inclined, and the eccentricity of the workpiece (3) is adjusted.

A machining center includes two independent carriages supported so that they can slide along respective longitudinal translation axes by two parallel horizontal rails fixed in a raised position to a supporting structure. The carriages support respective machining heads which can move along two respective translation axes. The machining heads support respective tool holding spindles in a rotatable manner about a horizontal rotation axis (Yr, Yr) by virtue of rotary support means. A workpiece holding table is supported at the base of the supporting structure. Two mechanized tool magazines are supported at the opposite longitudinal ends of the supporting structure and are accessible by the spindles. The rotary support and/or the workpiece holding table can rotate about a respective vertical axis.

A brake mechanism has a brake disk, multiple clutches, and multiple brake assemblies. The brake disk is coaxially connected to a rotatable work table. The multiple clutches are capable of clamping the brake disk. The multiple brake assemblies correspond in position to the multiple clutches. Each one of the multiple brake assemblies has a housing, an abutting shaft inserted in the housing, and multiple elastic units received in the housing and abutting against the abutting shaft. The multiple abutting shafts of the multiple brake assemblies abut against the brake disk for stopping the work table from rotating. A hydraulic system applies hydraulic pressure inside the multiple housings of the multiple brake assemblies and forces the multiple abutting shafts to depart from the corresponding clutch, making the work table rotate again.

A brake mechanism has a brake disk, multiple clutches, and multiple brake assemblies. The brake disk is coaxially connected to a rotatable work table. The multiple clutches are capable of clamping the brake disk. The multiple brake assemblies correspond in position to the multiple clutches. Each one of the multiple brake assemblies has a housing, an abutting shaft inserted in the housing, and multiple elastic units received in the housing and abutting against the abutting shaft. The multiple abutting shafts of the multiple brake assemblies abut against the brake disk for stopping the work table from rotating. A hydraulic system applies hydraulic pressure inside the multiple housings of the multiple brake assemblies and forces the multiple abutting shafts to depart from the corresponding clutch, making the work table rotate again.

A rotary table includes a clamping mechanism including a piston driven by operating fluid in a direction of either of clamping and unclamping a brake disc, and a biasing means fixed by a case and the piston to always bias the piston in a direction of either of clamping and unclamping the brake disc by a recovery force of elastic deformation.

A machine tool includes a rotation table unit including a rotation table configured to rotate with respect to a first axis. The rotation table unit is configured to move along a second axis that is orthogonal to the first axis. The machine tool includes a spindle unit including a spindle configured to rotate with respect to a third axis that is orthogonal to the first axis and the second axis. The spindle unit is configured to move along the third axis. The machine tool includes a bed that supports the rotation table unit and the spindle unit. A front part of an upper surface of the bed includes a recess in which the rotation table unit is arranged. The spindle unit is located at a rear part of the upper surface of the bed.