Modeling and Analysis of Temperature Rise in Ball Screw Pairs Considering Thermal Contact Resistance and Convective Heat Transfer Coefficient Corrections

To address the challenges of quantifying the contact thermal resistance caused by microscopic interfacial morphology in finite element thermal analysis of ball screw pairs and the variation of convective heat transfer coefficients under dynamic operating conditions, an equivalent loading method for contact thermal resistance in ball screw pairs is proposed and a thermal analysis model incorporating corrected contact thermal resistance and convective heat transfer coefficients is established. Based on the MB fractal theory, the contact thermal resistance between components of the ball screw pair is calculated, and the thermal boundary conditions of the screw under different operating conditions are determined. Temperature field simulation results for a specific screw model show that when contact thermal resistance is considered, the temperature differences between the screw/nut and nut/worktable interfaces increase across all operating conditions, with the maximum difference rising from 1°C to 7. 2°C. After accounting for convective heat transfer coefficient variations, the overall temperature rise of the screw decreases, and a 4.8°C temperature reduction is observed at the nut/worktable interface. Experimental measurements of the worktable temperature are conducted to validate the simulation model. Compared with experimental results, the calculation errors for temperature rise at the nut node decrease from 29. 5% to 3. 63%. and at the worktable node from 46. 8% to 5. 6% after implementing the proposed corrections. The developed thermal analysis model demonstrates applicability for temperature prediction in ball screw pairs under varying rotational speeds.