BALL SCREW DEVICE, INJECTION MOLDING MACHINE EQUIPPED WITH THE SAME, AND CONTROL METHOD FOR BALL SCREW DEVICE

摘要

PROBLEM TO BE SOLVED: To provide a ball screw device allowing a plurality of ball nuts to equally share load applied thereto without changing the mounting positions of the ball nuts to an acting body. SOLUTION: In this linear moving ball screw device for moving the acting body by one or more ball screw shafts and ball screw nuts, a plurality of ball screw nuts are screwed to the same ball screw shaft, and one of the plurality of ball screw nuts of each ball screw shaft is fitted to the acting body through a fixed flange. One of a plurality of fixed flanges is provided with a load detecting sensor, and the other ball screw nuts are made to be a ball screw nut fluid pressure support mechanism based on a cylinder and a piston. Fluid pressure is controlled so that the bearing power of the fluid pressure support mechanism is equal to the detected pressure of a load detecting sensor. Large load can be shared between the respective ball screw nuts.