Ball screw pair of axial clearance adjustment and preloaded classification method

Ball screw pair of axial clearance adjustment and pre-tightening methods classification, 2020 - 07 - 14 ball screw pair in addition to the single direction transmission precision requirements, also has strict requirements for the axial clearance, to ensure its return to the transmission accuracy. Axial clearance of ball screw pair is carrying the ball and raceway contact points nut displacement caused by elastic deformation and nut the sum of the original clearance. Usually adopt the method of double nut and tighten, control the elastic deformation within the minimal, to reduce or eliminate the axial clearance, and can improve the stiffness of ball screw pair. According to the axial clearance adjustment and pre-tightening methods are divided into four categories, respectively is double nut thread preloaded gap type, double nut gasket preloaded gap type, double nut gear differential preloaded gap type, spring loaded automatically adjust preloaded gap type. Double nut thread preloaded gap type structure, through a threaded lock nut and a round nut is fixed. Adjusted by rotating round nut and then use lock nut locking produce certain axial pre-tightening force, thereby eliminating the axial clearance. Is characterized by simple structure, good rigidity, preloaded and reliable, but generally precision. Double nut gear differential preloaded gap type structure, even have a nut at both ends of the two teeth difference is 1 of the cylindrical gear, through two internal gear and the gear meshing, and screw and dowel pin is fixed on the sleeve. Adjustment to remove internal gear at the ends of the first, as the two nut relative to the sleeve after the same force to rotate the same tooth fixed, a ball nut relative to another to produce relative displacement and pre-tightening force into eliminate axial clearance. Its characteristic is can achieve precise quantitative adjustment, reliable operation, easy to adjust, but the processing and assembly process complex. Ball screw pair in the ball movement characteristics. When the ball screw vice carry axial load, ball and screw groove and nuts raceway contact, the contact Angle of 45 & deg; The left and right sides. Ball movement along the spiral surface, the center of the ball trajectory in a ball center circle helix, ball and screw race track for a spiral surface contact.