Research on the Correction of the Linkage Hydraulic System of the Composite Hydraulic Gripper Used in Coal Mine Rigs

Abstract

Abstract The research against the defect that the gripper of the rig using a traditional linkage hydraulic system always clips back to damage drill pipes when the rig starts to rotate is presented. The correcting solution of a kinetic pressure feedback system including a damper and an accumulator is described by establishing the transfer function of the linkage system and analysing major factors making the gripper to clip back. Taking the ZYWL-4000SY automatic rig for instance, the linkage hydraulic system after correction is compared with that of before in simulating analysis and the correcting solution is verified by both lab and field tests. The results show that the corrected gripper works well without hurting pipes and the rig operates in good and stable condition. The theoretical foundation and method are provided to design and test the linkage function of the composite hydraulic gripper of other similar rigs.