摘要：The merits and demerits of the movable balance-weight schemes in the existing tower crane are summarized and analyzed. The new design of rotatable balance-arm, latticed crane head, platform and rotational upper support is put forward for top of crane SXD50. The rotatable balance-arm is composed of two parallel truss structures, platform, luffing mechanism and balance-weight. The balance-arm can be pulled to rotate around the rotational upper support by luffing mechanism under amplitude control system. The forward torque is equaled to the backward torque from the balance-arm to realize the moment equilibrium of crane body during working. The luffing mechanism of balance-arm on the platform can be as a part of balanceweight. The finite element model of balance-arm and crane head is built and the calculated results prove the rotatable balancearm system reliable and the structure strength satisfies the requirement of design.
