What is Main Structure of HZQ30/80 Launching Gantry?
The bridge girder launching gantry is made up of main girder, trolley, front support, middle support, rear support, electrical system and hydraulic system
HZQ30/80 launching gantry
1. Main girder
Main girder is made up of two parts: triangle honeycomb girder at left and triangle honeycomb girder at right. Each part has a total length of about50m. section to section connected by pin roll. The two parts main girders are connected by middle hoop beam and connection framework
2. Trolley
Made up of longitudinal moving gear box, heightening section, transverse moving beam and rail, transverse moving gearbox, trolley rack, winch, pulley block, hanging beam and connection framework
Trolley is the lifting mechanism. lower longitudinal moving mechanism makes trolley moves on rail on main girder; upper transverse moving mechanism makes trolley move on lateral sliding beam and rail; winch can lift the precast girder; above three parts and trolley steel structure as an unity finish lifting, moving, dropping precast girder and installing boundary girder as well as lifting small articles to front abutment; matched hanging beam has a wide use range to lift T type girder as well as box girder
3. Support
Front, middle, rear support and rear bracket. Front support and rear bracket have telescopic functions
Front support consists of bracket, internal sleeve, outer sleeve, connection beam, rotating connector, transverse moving gearbox, transverse sliding rail, front connection frame, fixing device, rail clamping device, hydro-cylinder and pin shaft.
Middle support: as a rear-end support when bridge girder launcher begins to install a girder, it is made up of roller institution, core tray, half curved beam, driving gearbox, driven gearbox, fixing device, transverse sliding rail and pin shaft.
Rear support is located in rear part of main longitudinal girder, made up of bracket, internal sleeve and outer sleeve. It is a rear-end support of bridge construction machine and a support for replacing support leg when moving from one pier to next pier.
Installed between middle support and rear support, rear bracket consists of hanging mechanism, roller mechanism, internal sleeve, outer sleeve, hydro-cylinder and pin shaft. As a rear end support to make main girder move forward when bridge construction machine installs a girder, the rear bracket could move at bottom of main girder with hanging mechanism, drive main girder to move forwards smoothly with roller mechanism. The internal and external sleeves can adjust the height of rear bracket to better adapt to crossing piers on slope bridge.
4. Hydraulic system
Made up of two groups of independent hydraulic stations on rear support leg and rear bracket , multiple directional control valve, cylinder and oil way. Located at the bottom of main girder, two hydraulic stations provide power for telescopic support legs
5.?Electrical system
Made up of motor and control cabinet with power about 75kw,? connected by cable, guide line and motor. Two control cabinets are fixed separately on rear parts of main longitudinal girder and lifting trolley. Control cabinet on trolley controls movement of trolley motor, while that on longitudinal girder controls crane?s longitudinal and transverse movement.
