A generalized measurement method of bending and torsional deformation for ball screws using bending-torsion decoupling

Journal article

Bending and torsional deformation of ball screws affect lead accuracy through distinct mechanisms and require separate evaluation for effective quality inspection and condition monitoring. However, both deformation modes coexist along the screw shaft and are coupled in the measured surface geometry, so that existing methods addressing them independently cannot provide reliable results under coupled conditions. This paper proposes a generalized method for measuring ball screw bending and torsional deformation when bending and torsion are coupled. An analytical model reconstructs the ideal screw surface directly from structural parameters and represents bending eccentricity and torsional angle as parametric functions along the rotational axis. Continuous rotational measurement is employed to acquire full-stroke three-dimensional surface point clouds, and a successive iterative least-squares algorithm is developed to jointly identify bending and torsion from the measured data. Numerical simulations on screws with different sizes, deformation modes, and noise levels confirm that the method maintains high identification accuracy and stability. Furthermore, an effective filtering method is introduced to suppress noise in the measured surface signals and improve the robustness of parameter identification. Experiments on three ball screws demonstrate good agreement with vision-based bending measurement and section-wise torsion comparison, confirming the method’s engineering applicability. The method enables decoupled extraction of bending and torsion components and provides a practical route for full-stroke quality inspection, process-oriented deformation evaluation, and condition monitoring of ball screws in manufacturing and service.

Authors: Wang, B; Pei, Y-C; Nie, Z-H; Zhao, Y-Z; Bai, S

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: Elsevier
• Journal: Measurement
• Volume: 282
• Article number: 121991
• Publication date: 2026-05-25
• Acceptance date: 2026-05-20
• DOI: 10.1016/j.measurement.2026.121991
• EISSN: 1873-412X
• ISSN: 0263-2241
• Language: English
• Keywords: ball screw; lead accuracy; deformation evaluation; bending-torsion decoupling; continuous rotational measurement