Optimal operating condition of precision ball screws based on a transmission efficiency model

Abstract

The operating condition of ball screws is generally applied to ensure the ball screws with a high transmission efficiency and a high positioning accuracy. Aiming at the optimal operating condition of double-nut ball screws, a transmission efficiency model considering the kinematic analysis and lubrication status was proposed. Firstly, the distributions of the film bearing pressure, asperity bearing pressure, film thickness, and ratio of the asperity bearing pressure were determined based on the Reynolds equation. Subsequently, the transmission efficiency model was established by calculating the friction coefficient and friction torque of ball screws under various lubrication statuses and operating conditions. The optimal operating condition of double-nut ball screws can be determined by estimating the transmission efficiency and lubrication status to improve the manufacturing quality. Finally, a friction torque test based on the simulated model was designed and implemented on a self-designed bed for validation of the proposed model. The comparisons showed that the experimental friction torque was consistent with the simulated friction torque, which verified the effectiveness and correctness of the transmission efficiency model. Results showed that the optimal operating conditions of the entrainment velocity and axial working load could ensure high transmission efficiency and a good lubrication status, which are of great reference to the green processing and manufacturing fields.