Moment limiter

The invention relates to a moment limiter, and belongs to the field of mechanical transmission. Comprising an input shaft, a raceway seat, a retainer, a baffle ring, a pressing sheet, a locking nut, a spring and a steel ball, wherein the raceway seat is of a hollow cylinder structure; the input shaft is coaxially butted with the input end of the raceway seat; the retainer is coaxially arranged at the output end of the raceway seat; the retainer extends into the raceway seat along the axial direction; the steel balls are uniformly arranged at the joint of the retainer and the raceway seat along the circumferential direction; the baffle ring is positioned on the side wall of the output end of the retainer; the steel ball is limited through the baffle ring; the output end of the holder is sleeved with the pressing piece. The springs are evenly arranged between the baffle ring and the pressing piece in the circumferential direction. The locking nut is sleeved on the end head of the output end of the retainer so a