Static Composite Kinematic Reliability Of Planar Path Mechanisms

The real mechanism motion system with uncertainty is inevitable because of the influence of factors such as dimensional tolerance,joint clearance,the elastic deformation etc.Uncertainty analysis and design with probability and statistics theory has formed a new discipline-mechanism motion reliability.The planar path generating mechanisms with dimensional tolerance and joint clearance on the influence of mechanism motion accuracy is studied in this paper.The each component error of output points exceeds permissible error limit is regarded as a kind of failure mode.The kinematic reliability analysis model of path generating mechanisms is then proposed with multiple failure modes.The static composite reliability at a specified time point is solved with the application of this model.A probabilistic model of each output component error is established by using the Hybrid Dimension Reduction Method(HDRM).The dimensional tolerance and joint clearance variables in the reliability analysis model are dealt with the HDRM.Then,deterministic synthesis model is proposed and solved based on the analysis of mechanism motion.The model of static reliability synthesis is proposed with the dimensional tolerance and joint clearance of path generating mechanism.Finally,the robust synthesis model is presented based on the mechanism motion accuracy and mechanism manufacturing cost.A numerical example is given to illustrate computational accuracy and efficiency of the proposed HDRM method.It is concluded that the optimal reliability synthesis solution is found with satisfying the requirement of mechanism kinematic reliability,the robust synthesis can make the real motion trajectory close to ideal mechanism motion trajectory and the mechanism has the lower manufacturing costs.