Portal crane structure

Portal cranes are generally composed of the following parts:

①Portal crane-structural part: including boom system, herringbone, rotating platform, driver's cab, gantry, etc.

②Portal crane-mechanism part: including lifting mechanism, luffing mechanism, rotating mechanism, and operating mechanism.

③Portal crane-electrical part: portal cranes are generally powered by cable drums or trench sliding wires and driven directly by electricity. Only when the power supply cannot be solved, composite drive devices such as steam power generation or diesel power generation are considered. The electrical part generally includes wires and cables, central collectors, motors, transformers, resistors, control cabinets, control consoles, lighting, etc.

④Portal crane-safety device part: including limit devices, overload limiters, buffers, wind and anti-skid devices, etc. Large portal cranes with a cab and machine room platform height exceeding 20m should consider installing an attached simple elevator.

The crane's rotating mechanism is installed on the base of the portal crane. The gantry base is actually the load-bearing part of the crane. There is a walking mechanism under the gantry base, which can walk on the track set on the ground. The arm and luffing mechanism of the lifting mechanism are also installed on the rotating mechanism. The four mechanisms work together to complete the installation of equipment or hull sections, or to load and unload cargo.

Vehicles can pass under the gantry base. The track gauges of portal cranes are 6m, 10.5m and 15m respectively.Portal cranes are usually powered by external power grids through flexible cables, and the large mechanisms are generally driven by three-phase induction motors.

Portal cranes have lifting, slewing, luffing and running mechanisms. The first three mechanisms are installed on the rotating part and participate in the operation in each cycle. The rotating part is also equipped with a tilting single arm or combined arm and a driver's cab that can pitch. The walking mechanism is installed at the bottom of the gantry to adjust the working position of the crane. The portal crane is also equipped with additional equipment such as telescopic funnel and belt conveyor to improve the productivity of the portal crane when loading and unloading bulk materials with grab bucket. In addition to electrical protection devices, it is also equipped with safety devices such as lifting weight or lifting torque limiter and crane rail clamp.