Workpiece support device
A workpiece support device including a base, an electrically conductive worktable rotatably supported with respect to the base, a motor, a reducer that transmits rotation of the motor to the worktable and reduces a speed of the rotation, and a metal adapter interposed between the worktable and the reducer to separate the worktable and the reducer from each other. The worktable and the adapter are electrically insulated by an insulating coating film formed by a surface treatment on a surface of the worktable or the adapter.
1 . A workpiece support device comprising:
a base;
an electrically conductive worktable rotatably supported around a rotational axis with respect to the base;
a motor;
a reducer that transmits rotation of the motor to the worktable and reduces speed of the rotation; and
a metal adapter interposed between the worktable and the reducer at a location recessed, in a direction along the rotational axis, from an end surface of the reducer to separate the worktable and the reducer from each other,
wherein the worktable and the adapter are electrically insulated by an insulating coating film formed by a surface treatment on a surface of the worktable or the adapter,
wherein the reducer includes a fixed portion fixed to the base, and a movable portion disposed radially outside of the fixed portion and rotatable around the rotational axis,
wherein the metal adapter is fixed to an annular flange surface extending radially outwardly from an outer peripheral surface of the movable portion, and
wherein a cylindrical portion extending along the rotational axis from the worktable is configured to radially cover a part of the adapter and a part of the movable portion.
2 . The workpiece support device according to claim 1 , wherein
the adapter has a ring shape and is interposed between the annular flange surface of the cylindrical portion of the reducer and an annular flange surface of the worktable,
the adapter has a contact surface that contacts the worktable and that is provided with the insulating coating film, and
the adapter has a plurality of through holes through which bolts that fasten the worktable and the reducer are inserted, and
wherein the worktable and the reducer are fastened together by the bolts with insulating washers having electrical insulating properties.
3 . The workpiece support device according to claim 2 , wherein
through holes into which the bolts are inserted and counterbores in which heads of the bolts are disposed are formed in one of the worktable and the reducer,
screw holes in which the bolts are tightened are provided in the other one of the worktable and the reducer, and
the insulating washers are interposed between seating surfaces in the counterbores and the heads of the bolts.
4 . The workpiece support device according to claim 3 , wherein the through holes in the worktable or the reducer and parts of outer peripheral surfaces of the bolts that are inserted into the through holes or inner peripheral surfaces of the through holes are covered with a coating containing an electrically insulating material or with an insulating coating film.
5 . The workpiece support device according to claim 1 , wherein the motor is fixed to the base, and the motor and the base are electrically insulated from each other by an electrically insulating material.
6 . A workpiece support device comprising:
a base;
an electrically conductive worktable rotatably supported around a rotational axis with respect to the base;
a motor;
a reducer that transmits rotation of the motor to the worktable and reduces speed of the rotation; and
a metal adapter interposed between the worktable and the reducer at a location recessed, in a direction along the rotational axis, from an end surface of the reducer to separate the worktable and the reducer from each other,
wherein the worktable and the adapter are electrically insulated by an insulating coating film formed by a surface treatment on a surface of the worktable or the adapter,
the motor is equipped with a toothed gear that transmits rotations of the motor to the reducer, and
an insulating coating film is formed by a surface treatment on a surface of the toothed gear of the motor.