Research on Problem of Feedback Mechanism Clearances of a Digital Hydraulic Cylinder for Shearer Rocker Arms.

In order to study the influences of feedback mechanism clearances on static errors and closed-loop stability of the hydraulic system of coal winning machine, the interaction mechanism of 4 kinematic pairs and their clearances in feedback processes was analyzed, and a digital hydraulic cylinder model with feedback mechanism clearances was established. By comparing the position relationship between negative inverse frequency curves of clearances and Nyquist curves of the linear parts, it is found that the clearances do not affect the stability of the system. Using the static analysis method, the static error expression caused by each clearances was derived, and the factors and laws affecting the static errors were revealed. The AMESim simulation model of digital hydraulic cylinder was established and simulated. Correctness of the theory and simulation analysis was verified by experiments. [ABSTRACT FROM AUTHOR]