What are Structures of Walking Type Launching Gantry?
Walking type launching gantry is a new type of bridge construction crane fabricated to meet demands of market and actual working condition, combined with current successful experience of ZZHZ and other companies.
walking type launching gantry
Walking type launching gantry is mainly made up of main guide beam, front guide beam, auxiliary push rod (front, middle), front support leg, middle support leg, rear support leg, lateral guide beam, longitudinal moving gearbox, lifting trolley, lateral rail, hydraulic system, electrical control system and other systems. Details are as below:
Main guide beam: honeycomb girder structure to bear weight of the whole precast girder, lifting trolley moves above main guide beam, longitudinal rail for front and middle support leg below it.
Front guide beam: honeycomb girder structure guides launching gantry to cross piers
Longitudinal moving gearbox: connect with front and middle support leg, lower chord of guide beam in the gearbox can realize longitudinal moving as lifting girders
Lifting trolley: be equipped with winch with slow speed, move on rail of lateral guide beam to realize lateral moving as lifting girders
Auxiliary push rod (front, middle): used in crossing piers process, help front and middle support legs to move longitudinally, adjust levelness of launching gantry main girder and bears part of weight of launching gantry. As hydraulic rods, auxiliary push rods are installed on fixed position of guide beam.
Lateral guide beam and lateral guide beam longitudinal moving gearbox: installed on upper chord of guide beam, front and rear longitudinally moving gearboxes can move the girder longitudinally. The gearbox is equipped with horizontal moving seat and rotating seat which can be adjusted to ensure an indeclinable rail gauge as constructing the skew bridge. At the moment vertical guide beam crosses obliquely with horizontal guide beam.
Front support leg: made up of lateral moving gearbox, support leg, adjusting rack, turn plate and longitudinal moving mechanism. Single rail for lateral moving gearbox which can move with self motor and realize lateral moving of launching gantry; support leg consists of standard section and adjusting section, whose height can be adjusted by hydro-cylinder jacking up. As installing the last girder, the standard section needs to be removed to ensure front support leg to stay on the bridge abutment. With large gradient and span, adjusting section and jacking cylinder also need to be removed
Middle support leg: the structure is same with that of front support leg, double rails for its lateral moving gearbox to ensure the stability of launching gantry. Turn plate is adjusted and fixed by screws to realize constructing skew bridge.
Rear support leg: fixed and installed at the position 1.5m-3m far near to rear part of the launching gantry, adjust height with attached jacking hydro-cylinder, main function: jack up guide beam and bear part weight of launching gantry as middle support leg moves forward.
