MOTOR-DRIVEN WORKING APPARATUS USING SERVO MOTOR

PROBLEM TO BE SOLVED: To provide a motor-driven working apparatus using a servo motor, in which a feed rate of a working tool to be fit to an edge tool chuck is made constant.SOLUTION: The motor-driven working apparatus 10 has; a motor unit 12 which has a stator 23 arranged in a stator holding case 22 and a rotor 24 including a spindle 27 in the central part thereof and arranged in an outer case 11; the edge tool chuck 41 to be fit to the front side of the spindle 12; and a forward/backward driving unit 14 for moving the motor unit 12 back and forth relatively to the outside case 11. The forward/backward driving unit 14 has: the servo motor 15 connected to a ball male screw 60 while interposing a coupling 61 between them; and a ball female screw 63 in which the ball male screw 60 is screwed. The ball female screw 63 is connected to a second bearing block 21a while interposing a power transmission metal fitting 64, which is projected from a notched part 20 formed on the outside case 11 into the outside, between the ball female screw and the second bearing block 21a, and the edge tool chuck 41 is moved back and forth by the rotation of the servo motor 15.