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EP-4520476-B1 - DOUBLE ROTATION INDEXING DEVICE

EP4520476B1EP 4520476 B1EP4520476 B1EP 4520476B1EP-4520476-B1

Inventors

  • DETO, Ryota

Dates

Publication Date
20260513
Application Date
20240828

Claims (1)

  1. A double rotation indexing device (1) including two sets of rotation indexing units (10 and 10), each of the rotation indexing units comprising: a main shaft (11) rotatably supported in a frame (2) and having one end side to which a rotation target member (12) is attached; and a drive transmission mechanism (30) configured to transmit rotation of an output shaft of a drive motor (3) to the main shaft (11), the drive transmission mechanism (30) including: a drive shaft (33) configured to being rotationally driven by the drive motor; a disk-shaped driven member (35) attached to the main shaft; and a drive member (34) provided on the drive shaft and having a spiral groove formed to engage directly or indirectly with the driven member(35), the drive shaft (33) being supported on one end (33a) side by the frame via a bearing holder (40) having a built-in thrust bearing (41) and being supported on the other end (33b) side by the frame via a radial bearing (43), the drive shafts of both rotation indexing units being connected by a connecting member (5), and the drive motor (3) being connected to an end portion, on an opposite side to the connecting member side, of the drive shaft (33) of one rotation indexing unit (10), characterized in that the other end (33b) of the drive shaft (33) in one rotation indexing unit (10) is connected to the other end (33b) of the drive shaft (33) in the other rotation indexing unit (10).

Description

TECHNICAL FIELD The present invention relates to a double rotation indexing device including two sets of rotation indexing units in which each of the rotation indexing units includes a main shaft rotatably supported in a frame and having one end side to which a rotation target member is attached and a drive transmission mechanism configured to transmit rotation of an output shaft of a drive motor to the main shaft, the drive transmission mechanism includes a drive shaft that is rotationally driven by the drive motor, a disk-shaped driven member attached to the main shaft, and a drive member provided on the drive shaft and having a spiral groove formed to engage directly or indirectly with the driven member, the drive shaft is supported on one end side by the frame via a bearing holder having a built-in thrust bearing and is supported on the other end side by the frame via a radial bearing, the drive shafts of both the rotation indexing units are connected by a connecting member, and the drive motor is connected to an end portion, on an opposite side to the connecting member side, of the drive shaft of one rotation indexing unit. BACKGROUND ART In the field of machine tools, a so-called multiple rotation indexing device is known which includes a plurality of sets of rotation indexing units for indexing an angular position of a workpiece. In the multiple rotation indexing device, the rotation indexing unit includes a main shaft rotatably supported in a frame and a drive transmission mechanism for transmitting rotation of an output shaft of a drive motor to the main shaft. In the rotation indexing unit, the main shaft is configured so that a rotation target member (for example, a table on which the workpiece is fixed) is attached to one end side of the main shaft. In addition, the drive transmission mechanism is configured to include a drive shaft that is rotationally driven by the drive motor, a disk-shaped driven member attached to the main shaft, and a drive member provided on the drive shaft and having a spiral groove that engages directly or indirectly with the driven member. As an example of the multiple rotation indexing device having a plurality of such rotation indexing units, there is a device disclosed in Patent Literature 1. As for the multiple rotation indexing device disclosed in Patent Literature 1, which forms the basis for the preamble of claim 1, specifically, in each rotation indexing unit of the multiple rotation indexing device, the drive transmission mechanism is configured as a worm gear mechanism including a worm shaft as the drive shaft that is rotationally driven by the drive motor, a worm as the drive member provided on the worm shaft, and a worm wheel as the driven member attached to the main shaft. As is well known, the worm gear mechanism is configured so that the worm wheel directly (meshes) engages with a worm groove formed in a spiral shape on an outer periphery of the worm. In addition, in the drive transmission mechanism of the rotation indexing unit, the worm shaft is supported with respect to the frame via a bearing. However, support on one end side of the worm shaft is made via a ball bearing as a thrust bearing, and support on the other end side is made via a roller bearing as a radial bearing. That is, in supporting the drive shaft (worm shaft) in the drive transmission mechanism (worm gear mechanism) as described above, a thrust bearing (ball bearing) that can receive a load in an axis line direction (thrust direction) of the drive shaft is adopted for support on one end side so that a position of the drive member (worm) does not change in the axis line direction under a reaction force from the driven member (worm wheel). In addition, as in the multiple rotation indexing device of Patent Literature 1, support on one end side by the thrust bearing is made in such a form that a bearing holder (bearing housing) having a built-in thrust bearing is attached to the frame. Specifically, in the drive transmission mechanism, the position of the drive member in the axis line direction needs to be a desired position where engagement with the driven member is properly made. Therefore, when mounting the drive shaft, on which the drive member is provided, to the frame, it is necessary to perform the mounting along with position adjustment (alignment) of the drive shaft so that the position of the drive member in the axis line direction becomes a desired position. Note that since the radial bearing used for support on the other end side is a bearing specialized for receiving a load in a radial direction, the radial bearing is generally provided in a state in which displacement in the axis line direction is allowed with respect to the frame. On the other hand, since the thrust bearing used for support on one end side is a bearing for receiving a load in a thrust direction in addition to the load in the radial direction, the thrust bearing is provided in a state in which displacement in