Double girder cranes are widely used, with their operation primarily consisting of three movements: the trolley moving vertically, horizontally, and the lifting hook moving left and right.

The hoisting transmission system of the double girder crane: The power unit of the lifting mechanism is transmitted from the motor, which is then conveyed to the high-speed shaft end of the reducer through a gear coupling, a compensating shaft, and a brake wheel coupling. After the motor rotates at high speed and is reduced to the required speed ratio by the reducer, the slow-speed shaft of the reducer inputs and outputs driving force, which is then transmitted to the drum group through the inner gear ring inside the drum. Finally, it is adjusted by galvanized steel wire rope and pulleys as the lifting hook to achieve the effect of adjusting the load.

Double girder crane trolley running system transmission: Drive force is transmitted from the motor through a brake wheel coupling, a compensating shaft, and a half tooth coupling to the high-speed shaft end of the vertical reducer. After the motor rotates at high speed and is reduced to the required speed ratio by the vertical reducer, it is output from the slow-speed shaft of the reducer. The slow-speed shaft is connected to the car's rotating shaft via a half-tooth coupling, a compensating shaft, and another half-tooth coupling, thereby rotating the trolley's rotating shaft and achieving the effect of lateral transport and lifting of the load.

The drive system of the double girder crane's trolley running system: The driving force is transmitted from the motor through a brake wheel coupling, a compensating shaft, and a half tooth coupling to the high-speed shaft end of the reducer. After the motor's speed is reduced to the required rate through the reducer, it is output from the slow-speed shaft of the reducer. The low-speed shaft connects to the trolley's rotating shaft through a full-tooth coupling, thereby driving the rotation of the trolley's rotating shaft, achieving the effect of vertically lifting the load on the bridge.