| 摘要 |
PROBLEM TO BE SOLVED: To provide a feed driving device capable of dispensing with a hydraulic cylinder of large stroke, minimizing the amount of oil necessary for a hydraulic balance cylinder for balancing the load, and vertically feeding a moving body such as a spindle head while keeping the load balance. SOLUTION: This feed driving device comprises a ball screw 22 vertically entended and rotationally driven by a driving motor 20, a feed nut 26 fixed to the moving body 10 and transforming the rotation of the ball screw 22 into the vertical motion of the moving body 10, a hydraulic balance cylinder 30 connected to a lower part of the feed nut 26 and producing the supporting force to be balanced with a weight of the moving body 10, a supporting nut 28 engaged with the ball screw 22, connected to the hydraulic balance cylinder 30 through a key 31, and receiving the load of the moving body 10 when the supporting force is produced by the hydraulic balance cylinder 30, and a lower bearing 24 supporting the load of the moving body 10 applied to the ball screw 22 through an upper bearing 23 supporting an upper end part of the ball screw 22 and the supporting nut 28.
|
