Retraction anti-backlash buffer structure of vertical lifting device

The utility model discloses a retraction anti-backlash buffer structure of a vertical lifting device, and belongs to the technical field of electromechanical structures. The buffer structure comprises a fixed cylinder, a lifting rod, a guide block and a clearance wheel; groove-shaped guide rails are evenly distributed in the fixed cylinder in the circumferential direction, and the lower portions of the groove-shaped guide rails are closed. The clearance wheel is movably mounted at the upper end of the groove-shaped guide rail; the outer diameter of the upper end of the lifting rod is larger than that of other parts, the guide block is fixed to the outer circumferential face of the lower end of the lifting rod, and the lifting rod is in large-gap sliding fit with the groove-shaped guide rail in the fixed cylinder only through the guide block at the early stage of retracting into the fixed cylinder; at the last stage of retracting the fixed cylinder, the surface of the clearance wheel is in contact with the out