Investigation of the fluctuation of the static axial rigidity for double-nut preloaded ball screws

Abstract

This article aims to investigate the fluctuation of the static rigidity for preloaded ball screws. Based on the correlation between preload and friction torque, a new model to calculate the contact rigidity by friction torque is proposed. Meanwhile, a novel test bench is constructed to measure the static stiffness at different positions. The experimental results agree well with the theoretical values, which proves the validity of the model. Furthermore, it is found that the screw shaft rigidity has the greatest influence on the system stiffness fluctuation, compared to the bearing rigidity, and the torsional rigidity. For the feed system, increasing the bearing rigidity, which is the lowest stiffness of the whole system, is an effective method to increase the system stiffness. The study provides an accurate method to obtain the stiffness fluctuation in the effective travel of ball screws, which is significant for improving the positioning accuracy of ball screws and computer numerical control machine tools.

Dynamic characteristics and reliability analysis of ball screw feed system on a lathe

“…The research of Liu and Ou [17] focused on the axial dynamic contact stiffness analysis of ball screws considering the balls' centrifugal force and gyroscopic moment with the screw's high rotational speed. The fluctuation of static rigidity based on the effect of friction torque on preload for ball screws has also received great attention [18] .…”

Optimization measurement for the ballscrew raceway profile based on optical measuring system

“…The parameters of ballscrew raceway profile directly determine the load distribution in ball screws, affecting their contact stiffness and friction characteristics [3][4][5]. In response to developments in the modern manufacturing industry, positioning accuracy and precision retention are becoming increasingly important, underlining the fundamental importance of machining accuracy detection for ball screws [6,7]. To date, many studies have concentrated on screw thread detection [8][9][10][11][12][13], whereas the study of the ballscrew raceway profile is relatively hysteretic.…”