Electromechanical coupling measurement of new giant magnetostrictive structure for double-nut ball screw pre-tightening

摘要

Under the action of an external magnetic field, giant magnetostrictive material (GMM) is magnetized and generates magnetostriction, so its dimension will change accordingly. In this work, two giant magnetostrictive structures are proposed for ball screw pre-tightening, but a finite element calculation shows that solid cylindrical GMM is better than a hollow one because it has a more uniform magnetization intensity. So a solid cylindrical GMM is used to build a ball screw pre-tightening structure. Experiments show that when the working current changes from - 3 A to 3 A, the magnetostrictive structure made of phi 10 x 120 mm GMM will output magnetostrictive deformation in the form of pre-tightening force, which is up to 1892.87 N. The axial rigidity performance of ball screw is improved by pre-tightening force adjustment. This research not only lays the theoretical and experimental foundations for applying a giant magnetostrictive structure to double-nut ball screw pre-tightening, but also provides a new method for the timely adjustment of a double-nut ball screws pre-tightening force.