Four-rope multi-rate winding system for large bridge crane

The invention discloses a four-rope multi-rate winding system for a large bridge crane, and relates to the technical field of hoisting mechanical equipment. The winding system comprises four winding drums which are symmetrically arranged on the left outer side and the right outer side of a lifting beam and are arranged in a vertical layered mode, a plurality of fixed pulley blocks installed on lifting beam webs, a balance pulley block hung in the axial plane of the fixed pulley blocks, movable pulley blocks installed at the upper ends of lifting hook pulling plates, lifting hook assemblies installed on the lower end portions of the lifting hook pulling plates and steel wire ropes used for winding and connecting all the parts into a whole. It is ensured that the four steel wire ropes do not interfere with one another in the winding process between the movable pulley blocks and the fixed pulley blocks through the four left and right duplex winding drums and the duplex pulley blocks or the quadruple pulley block