| 摘要 |
PURPOSE:To prevent variation in revolutional torque of a ball screw system and production of a backlash thereof by dividing a nut part into two nuts, sensing a reaction force in the feed shaft of both the nuts, and placing relative revolutional quantity of both the nuts under the negative control. CONSTITUTION:When a reaction force is produced between both nuts 1 and 2 during revolution of the ball screw shaft 4 due to lead error thereof, the intensity of the reaction force is sensed by a reaction force sensor 23. When the detecting signal of the reaction force sensor is sent to a main controller 24, the main controller drives a fine-revolution mechanism 15 via a fine- revolution mechanism driver 21, whereby a little varying relative revolutional quantities of both nuts. Variation rate of revolutional torque of the ball screw shaft is thereby moderated so that stable feeding operation having high precision can be attained. |
