Surface temperature and wear particle analysis of vertical motion double-nut ball screws

Abstract

PurposeThis paper aims to investigate the temperature and wear properties of vertical ball screws and to discuss the surface design of ball screws in industrial applications.Design/methodology/approachThe energy equation of the screw surface considering the frictional heat was established to verify the surface temperature of the ball screw. X-ray diffraction was used to examine the micro-contact temperature between the ball and screw. Debris size and density were examined to investigate wear properties of ball screws and to study the relationship of wear debris and temperature.FindingsFirst, the main energy source for the surface temperature of high speed vertical ball screws is derived from friction force between ball and screw. Second, the temperature rise between the ball and screw has great relevance with wear debris concentration. Third, the surface temperature of the screw is higher than between the nut and ball for high speed vertical ball screws due to high convection heat transfer. The contact temperature of the nut near the flange is smaller than that of the nut away from the flange end due to the high contact load and thermal conduction. Finally, correlation of particle size and surface roughness value for vertical ball screws was established, and its effects on contact temperature were studied. The theoretical analysis and experiments will help to characterize the design and manufacture of vertical ball screws.Originality/valueThe surface temperature and micro-contact temperature analytical model were established to study the ball screw design. Based on the surface-particle micro-contact temperature balance, the optimal range of surface roughness was designed for vertical ball screws, considering the wear debris and micro-contact temperature.