拉索式组合臂架门座起重机变幅机构的简图如图1所示,它由臂杆1、拉索2和象鼻梁3等组成。当一台门座起重机安装或大修结束前,都要进行货物移动路线的水平性检查,要求水平误差ΔH满足ΔH<0.02(R_(max)-R_(min))。式中R_(max)及R_(min)为最大和最小幅度时,杆 Figure 1 shows the cable luffing boom gantry crane luffing mechanism, which consists of the arm 1, cable 2 and the nose bridge 3 and other components. When a gantry crane is installed or undergoing overhaul, a horizontal inspection of the moving route of the cargo shall be carried out, and the horizontal error ΔH is required to satisfy ΔH <0.02 (R_ (max) -R_ (min)). Where R_ (max) and R_ (min) for the maximum and minimum amplitude of the rod