Special Conditions Bearing Characteristics Of The Ball Screw And Return

Precision ball screw is an important linear driven component in the application of aerospace. It is necessary to research the bearing captivity and the designation. This paper focuses on the bear capacity, the motion characteristics, the designation of return system and some other aspects in special conditions based on the elastic-plastic theory, the kinematic theory and the dynamic theory.First, establish the elastic-plastic contact model based on Hertz contact theory, and acquire the formula for the calculation of the elastic-plastic deformation consequently. the factors affected the bearing capacity are analyzed, and establish the finite element contact model. Obtain the plastic deformation critical load, the maximum load before the ball screw fails and the finite element results by modifying some parameters of the screw, through the theory calculation and finite element analysis. Second, the ball's movement characteristics are analyzed, the mechanism of the wedging effect and the sliding characteristic are emphasized. Obtain the effect of ball movement on the ball screw performance will be even more in special conditions. Finally, a new ball-returning curve for the ball screw is designed which is suitable in big load situation combined the popular sine ball-returning curve and the five parabolic ball-returning curve and the continuity is verified. Simulate the designed return system and the ideal results are obtained.This thesis work has a certain theoretical value and significance to improve the ball screw performance in aerospace engineering and enhance our ball screw design level.