Analysis for the trajectory error of the lower hook mechanism in netting machine

The lower hook mechanism in netting machine is a planar composite mechanism composed of double cams and six links. Due to the long transmission chain, the accumulated errors generated during its motion will cause the lower hook to deviate from the ideal trajectory, which may cause the lower hook to collide with other components. In response to the above-mentioned problem, the coupling effects of error sources such as manufacturing tolerances, kinematics pair clearance, hinge wear, component elastic deformation, and cam wear are comprehensively considered, and an analysis method for the motion error of the lower hook mechanism is proposed in this paper. By analyzing the error calculation results, it can be known that among all error sources, cam wear has the most significant impact on the trajectory error of the hook tip. Therefore, the cam manufacturing materials and processing technology should be considered to increase the wear resistance of cams.