Abstract: A machine tool includes a rotation indexing device and an abnormality determination device. The rotation indexing device including a clamp device configured to maintain a rotary shaft at an indexed angular position and an air purge device configured to supply compressed air to a space within a frame. The abnormality determination device includes a pressure sensor configured to output a pressure signal according to a pressure in a supply pipe conduit of the air purge device, and a determinator configured to determine presence or absence of an abnormality, based on the pressure signal from the pressure sensor.

Abstract: An indexing device includes a drive transmission mechanism, a fixing mechanism. The drive transmission mechanism includes an intermediate gear which includes an intermediate shaft being inserted at an end portion into an accommodation hole formed in a frame, and the intermediate shaft includes an accommodating concave portion and a plurality of through-holes. The fixing mechanism includes a cylindrical pressing member, steel balls and a screw member. There is a gap between the pressing member and a bottom surface of the pressing member in a state in which the pressing member is accommodated in the accommodating concave portion and the steel ball accommodated in each through-hole is in contact with a tapered surface and an inner peripheral surface of the accommodation hole.

Abstract: A rotary table device includes a table provided on one end-side of a main shaft rotatably supported in a frame; and a drive transmission mechanism transmit rotation of an output shaft of a drive motor to the main shaft and including a drive transmission member and accommodated in an accommodation space formed in the frame. The table is supported with respect to the frame by a bearing provided between a lower surface of the table and an upper surface of the frame, and a space is provided between the lower surface of the table and the upper surface of the frame. The frame is provided with a communication passage configured so that the space and the accommodation space communicate with each other.

Abstract: A machine tool includes a rotation indexing device and an abnormality determination device. The rotation indexing device including a clamp device configured to maintain a rotary shaft at an indexed angular position and an air purge device configured to supply compressed air to a space within a frame. The abnormality determination device includes a pressure sensor configured to output a pressure signal according to a pressure in a supply pipe conduit of the air purge device, and a determinator configured to determine presence or absence of an abnormality, based on the pressure signal from the pressure sensor.

Abstract: An indexing device includes a drive transmission mechanism, a fixing mechanism. The drive transmission mechanism includes an intermediate gear which includes an intermediate shaft being inserted at an end portion into an accommodation hole formed in a frame, and the intermediate shaft includes an accommodating concave portion and a plurality of through-holes. The fixing mechanism includes a cylindrical pressing member, steel balls and a screw member. There is a gap between the pressing member and a bottom surface of the pressing member in a state in which the pressing member is accommodated in the accommodating concave portion and the steel ball accommodated in each through-hole is in contact with a tapered surface and an inner peripheral surface of the accommodation hole.

Abstract: A rotary table device includes a table provided on one end-side of a main shaft rotatably supported in a frame; and a drive transmission mechanism transmit rotation of an output shaft of a drive motor to the main shaft and including a drive transmission member and accommodated in an accommodation space formed in the frame. The table is supported with respect to the frame by a bearing provided between a lower surface of the table and an upper surface of the frame, and a space is provided between the lower surface of the table and the upper surface of the frame. The frame is provided with a communication passage configured so that the space and the accommodation space communicate with each other.

Abstract: A rotation indexing device includes a rotary body having a main shaft rotatably supported via a bearing in an accommodating hole of a frame and a table part provided on one end-side of the main shaft, a workpiece or a jig for attaching the workpiece being attached to the table part; an oil seal provided in a void portion, which is a portion on the one end-side relative to the bearing, in a space between the frame and the rotary body; a drive mechanism configured to rotationally drive the rotary body; and a holding mechanism for holding the rotary body at an indexed angular position during indexing processing. A dust seal is provided in the void portion on an opposite side to the bearing-side with respect to the oil seal.

Abstract: Provided is a rotation drive device, which has a driving-force transmission mechanism configured such that a drive transmission member provided on a driving shaft and a disk-shaped driven member attached to a main shaft are directly or indirectly engaged with each other and which is further configured such that an increase in diameter of the driven member due to thermal expansion can be suppressed as much as possible. The driven member includes an inner ring attached to the main shaft, and an outer ring attached to the inner ring by shrinkage fit and having an engaging groove formed to be opened on an outer circumferential surface thereof. The inner ring is formed by a low thermal expansion member, which is an alloy having a thermal expansion coefficient of 5×10?6/K or less. The outer ring is formed of a hardenable iron-based material.

Abstract: A rotary table device for a machine tool includes a main shaft that is rotatably supported in an insertion hole formed in a frame; a table that is secured to an end side of the main shaft, and on which a workpiece, serving as an object to be processed, is mounted; a clamp piston that is provided so as to be movable in an axial direction of the main shaft in the insertion hole; and a bearing that is provided between the table and the frame, and that directly supports the table with respect to the frame. The main shaft has a clamp surface facing the table. A pressure chamber is defined by the frame and the clamp piston. When an operating fluid is supplied to the pressure chamber, the clamp piston is caused to press-contact the clamp surface, so that the table is brought into a clamped state.

Abstract: Provided is a clamp device of an indexing apparatus that indexes a main shaft, which is rotatably supported in an accommodation hole of a frame via a bearing, to a set angular position by rotating the main shaft by using a driving device. The clamp device includes a working channel that connects an air supply device, which supplies compressed air, to a pressure chamber in the clamp device. The clamp device operates to retain an angular position of the main shaft when compressed air is supplied from the air supply device. The clamp device includes a pressure transmitting portion that is interposed in the working channel and in which a piston is slidably disposed. A portion of the working channel on the pressure chamber side of the piston in the pressure transmitting portion is filled with an incompressible fluid.

Abstract: A rotary table device for a machine tool includes a main shaft that is rotatably supported in an insertion hole formed in a frame; a table that is secured to an end side of the main shaft, and on which a workpiece, serving as an object to be processed, is mounted; a clamp piston that is provided so as to be movable in an axial direction of the main shaft in the insertion hole; and a bearing that is provided between the table and the frame, and that directly supports the table with respect to the frame. The main shaft has a clamp surface facing the table. A pressure chamber is defined by the frame and the clamp piston. When an operating fluid is supplied to the pressure chamber, the clamp piston is caused to press-contact the clamp surface, so that the table is brought into a clamped state.