Chinese Space Science and Technology ›› 2018, Vol. 38 ›› Issue (4): 51-61.doi: 10.16708/j.cnki.1000-758X.2018.0036

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Motion characteristics of pointing mechanism with clearance in consideration of wear

HAN Xueyan1,2, LI Shihua1,2,*, ZUO Yaming2, LI Jun2   

  1. 1. Parallel Robotand Mechatronic System Laboratory of Hebei Province, Yanshan University, Qinhuangdao 066004, China

    2. College of Mechanical Engineering, Yanshan University, Qinhuangdao 066004, China

  • Received:2017-12-20 Revised:2018-01-25 Accepted:2018-05-15 Online:2018-08-25 Published:2018-05-16
  • About author:李仕华(1966-),男,教授,shli@ysu.edu.cn,主要研究方向为并联机器人理论及应用和空间机构非线性动力学与精度等

Abstract:

For the accurate prediction of the joint dynamic wear, the coupling factors of clearance, friction and abrasion were considered. The dynamic problems and abrasion problems of the twodimensional space pointing mechanism were studied, which considered the factors of clearance, friction and abrasion. Using the Newton Euler’s law, the dynamic model of the twodimensional space pointing mechanism with clearance was constructed by embedding the clearance variables. Based on the Archards wear model, by finding the wear depth at different positions of the moving contact surface and reconstructing the surface morphology of the kinematic pair, the dynamic characteristics of the pointing mechanism with clearance were analyzed in the process of wear, and the change laws of the contact collision force and the tangent friction force at the joints were obtained; the dynamic fitting variables method and the discrete processing method were used to fit the correspondences between the clearance and contact force, and the running time and the relative slip velocity of the kinematic pair with clearance, and  the dynamic wear mathematical model was established; furthermore, the predicted service lives of the two dimensional pointing mechanism are 12591.92 hours and 764.44 hours under the tracking mode and the attitude adjustment mode. The work in this thesis provided the theoretical base for the ontology design, manufacture and application of the two dimensional pointing mechanism.

Key words: pointing mechanism, ynamics, clearance, abrasion, life prediction