Structure Design of Detachable Knotter mouth and Its Fatigue Performance Analysis

Abstract

Knotter mouth is the key part of the knotting on the knotter. Under the action of variable amplitude cyclic load, such as extrusion, shear, torsion and so on, the surface wear of knotter pliers and the fracture of clamp hooks are easy to occur. It takes a long time to disassemble and assemble the knotter mouth, which seriously affects the field operation efficiency of the square baler. In view of the present situation that the knotter mouth of D-type knotter is easy to fail and difficult to replace, on the premise of not affecting the normal knotting function of the knotter, the detachable knotter mouth is designed and completed by reasonably designing the thread structure and rotation direction of the knotter mouth. The disassembly and assembly time is significantly reduced, which is beneficial to the continuous operation of the square baler. ANSYS simulation analysis shows that, compared with the original knotter mouth, the maximum equivalent stress and maximum equivalent strain of the detachable knotter mouth are increased by less than 3%, and the maximum impact fatigue life of the detachable knotter mouth is 60 000 times. The fatigue life of the knotter mouth is much lower than that of the original knotter mouth, but it can still meet the rated life requirements of 40, 000 knotting times of the knotter. The research content makes full use of the safety margin of the knotter mouth structure, which has reference value for facilitating the maintenance and replacement of the knotter mouth and improving the operation efficiency of the whole machine.