On the Results of Investigating the Efficiency of Ball Screws with Separators

Abstract

Extensive use of ball screws with separators is due to manufacturing simplicity and increased reliability as compared to ball screws with recirculating rolling elements. The issues of determining the efficiency of such mechanisms have not been sufficiently studied. The paper presents analytically derived primary dimension ratios for parts of ball screws with separators, taking into account those tolerances that should be observed to ensure that the mechanism assembly is guaranteed and the preloads affecting the breakaway forces and the mechanism efficiency are prevented. We provide guidelines for designing parts of ball screws with separators. We plotted the interacting forces in the parts constituting ball screws with separators and analytically determined the efficiency of such mechanisms as a function of contact angles and lead angles. The experimental investigation results concerning electro-mechanical drive prototypes based on ball screws confirm the analytical expressions obtained. Adhering to the dimension ratios proposed for parts of ball screws with separators reveals that the analytically and experimentally determined efficiency values converge. Using the efficiency plots presented for ball screws with separators while designing electromechanical drives is appropriate to assess energy losses in mechanical transmissions