CHEN G Q, CHU Z X, KANG J L, et al.Dynamic analysis of parallel mechanism with mixed clearance of rotating pairs and spherical pairs[J].Journal of Henan Polytechnic University(Natural Science) ,2026,45(1):110-117.

doi:10.16186/j.cnki.1673-9787.2021100059

Received:2021/10/25

Revised:2022/03/09

Published:2025-12-03

Dynamic analysis of parallel mechanism with mixed clearance of rotating pairs and spherical pairs

Chen Guoqiang, Chu Zixin, Kang Jianli, Zhang Dengpan, Li Tian

School of Mechanical and Power Engineering， Henan Polytechnic University， Jiaozuo 454000， Henan， China

Abstract: Objectives In order to study the effect of various clearances on the dynamic characteristics of parallel mechanisms， the dynamic model of the 3-PRS parallel mechanism with mixing clearances of rotating pairs and spherical pairs was established and the dynamic analysis was carried out in this paper. Methods Firstly， kinematic analysis was conducted on the position， velocity and acceleration of the 3-PRS parallel mechanism； the kinematic models of the clearance rotating pair and the clearance spherical pair based on the “contact-separation” two-state model were established. Secondly， the Flores contact model and the modified Coulomb friction model were used to establish the contact force model. Then， the Newton-Euler method was used to establish the dynamic model of the 3-PRS parallel mechanism with mixed clearance. Finally， through simulation experiments， the influences of mixed clearance， different clearance values， and different drives on the dynamic characteristics of the parallel mechanism were compared and analyzed. Results The results showed that the motion trajectories of the mechanism with mixed clearance and the mechanism without clearance in the ideal state tended to be consistent as a whole. However， the mixed clearance causesed the mechanism to deviate from the ideal position during motion， resulting in fluctuations in velocity and more frequent sudden changes in acceleration. By comparing different clearance values， when the clearance increased， the later the mechanism reached stable operation time， the greater the position offset， the greater the speed fluctuated， and the more unstable the mechanism operated.By comparing different drives， when the drive amplitude decreased， the mechanism reached stable operation earlier， the position and speed curves were smoother， and the mechanism was more stable. Conclusions The research results showed that the mixed clearance had a serious impact on the moving speed， acceleration and other dynamic characteristics of the parallel mechanism. This research could provide a method and theoretical basis for analyzing the actual movement of the 3-PRS parallel mechanism and the control of clearance errors.

Key words:parallel mechanism;clearance;contact force;dynamics;dynamic characteristic