Study on the thermo-mechanical performance of ball screw pair under combined loads

Abstract

During operation, the ball screw feed system of CNC machine tools generates frictional torque and frictional heat, and its performance is significantly influenced by the thermodynamic behavior of internal heat sources. As a key component of the feed system, the contact characteristics of ball screw pairs directly determine their thermal response, which affects both positioning accuracy and service life. To address limitations in current studies, this work proposes a self-regulating load-torque distribution model to systematically evaluate the effects of combined loading conditions on heat generation rate, stress distribution, and contact behavior. The proposed model is validated through numerical simulations and existing benchmark data. The results show that it accurately captures the static load distribution under geometric deviations. The developed model enhances understanding of load-bearing behavior and reveals the intrinsic coupling between thermal response and geometric errors. Under external loading, geometric deviations alter contact angle distribution, modify force transmission paths, and increase localized heat generation, ultimately leading to thermal accumulation and performance degradation. Moreover, axial force imbalance caused by non-uniform contact loads aggravates dynamic responses and reduces system stability. This study contributes to the theoretical framework of ball screw systems under multi-parameter loading and provides a practical reference for optimizing thermal performance and reliability in precision feed applications.