Abstract:

Non continual- contacting model and the use of the equivalent length theory is introduced in this article. Considering the manufacturing error and the wear or assembly clearance , Kinetic models are established for the spatial four-bar mechanism and the planar four-bar mechanism of the spatial linkage weft insertion mechanism based on the probabilistic analysis method and non-continual contacting theory. The movement simulation and related curve is carried by the calculation and simulation module of MATLAB. The influence of size error and clearance to the mechanism motion output is analyzed in detail. When considering the component error and clearance between the kinematic pair ，the output error of sword head is more obvious than considering a factor only, the maxima error is near the maximum point of the speed, which indicates that the influence of clearance and component error in high-speed mechanism is particularly serious, The results of this study can provide reference for the research of motion accuracy of spatial four bar weft insertion mechanism.

Key words: weft insertion mechanism, non continual-contacting model, ciearance, equivalent length theory, dimensional error