摘要:During the luffing of the portal crane, the height changing of the center of gravity of the boom needs to consume extra energy, which not only wastes energy, but also makes the luffing drive system need to use a larger motor. This paper uses the lever-movable counterweight balance method to design the self-weight balance of the portal crane, and verifies that the designed jib self-weight balance system meets the requirements of the maximum height deviation, unbalanced torque and comprehensive unbalanced torque by evenly taking points. The power and unnecessary energy consumption of the luffing drive mechanism are reduced.