Design and dynamic characteristic analysis of the planetary roller screw mechanism for all-electric injection molding machines
YAN Weiliang
Abstract：[Objective]To explore the transmission structure of a fully electric injection molding machine adapted for large tonnage and high injection pressure,this study focuses on the planetary roller screw pair of the injection unit based on the injection process flow and process parameters of a 350 t fully electric injection molding machine.The research involves thread profile design and parameter calculation,screw thread modification,displacement design of the roller external teeth and nut internal tooth ring,as well as component structural design.[Methods]Through virtual assembly,the relation between the initial positions of each roller and the assembly reference during assembly was summarized.A virtual simulation prototype of the planetary roller screw pair was established.Using Adams software,the dynamic characteristics of the mechanism were simulated and analyzed,and theoretical data were compared with simulation results.[Results]The results indicate that the maximum error between the simulated and theoretical angular velocities is 2%,validating the accuracy of both the design and simulation models.The clearance in the thread pair affects the nut acceleration and the contact force on the thread surface.Specifically,larger thread clearance results in smaller contact forces on the thread surface,whereas smaller clearance leads to greater contact forces.
Keywords：All-electric injection molding machinePlanetary roller screw pair designDynamic
Publication Date：2026-04-15
Online Publishing Date：2026-09-12(First online date of this platform, not the publication date of the document)
Pages：10( 91-100 )