General purpose overhead crane
QD/LH Type Double Girder Overhead Crane
Product Overview
The QD/LH Type Double Girder Overhead Crane is a heavier-duty bridge crane built for higher lifting capacities and longer spans than single girder designs allow. Two parallel girders support a crab trolley that runs on rails along their top flanges, giving the crane the stiffness and hook height needed for demanding industrial applications.
Structure Composition
- Main Girders: Two parallel box-type steel girders form the bridge, providing high bending and torsional stiffness across long spans.
- End Trucks: Carry the wheel assemblies that run on the elevated runway rails.
- Crab Trolley: Runs on rails along the top of the main girders, housing the hoisting drum, motor, gearbox, and brake.
- Operator Cab or Remote Control: A cab suspended beneath the bridge is common at this duty level, though remote control is increasingly used to reduce staffing needs.
- Electrical System: Conductor rail or festoon cable power supply, with PLC-based control for higher-duty operation.
Application
- Steel mills, foundries, and metal fabrication plants
- Heavy machinery assembly and production lines
- Power plants and process industries
- Any facility requiring frequent, high-capacity, or continuous-duty lifting
Key Features
- Higher lifting capacity and greater hook height than single girder cranes, due to the crab trolley running on top of the girders rather than underneath
- Greater structural stiffness suited to long spans and heavy, frequent-cycle operation
- Can be equipped with dual hoists (main and auxiliary) for handling loads of different sizes on the same crane
- Rated for heavy-duty working class, suitable for continuous industrial production environments
Technical Parameters (Reference Range)
Lifting Capacity: 5–500 t
Span: 10.5–31.5 m
Lifting Height: 6–30 m
Working Class: A4–A7
Control Mode: Cab, pendant, or remote control
Safety Devices
Overload limiter, hoist and travel limit switches, anti-collision devices, sound and light alarms, emergency stop system, buffer stops, and rail sweeps.
Customization Options
Single or dual hoist configuration, span and capacity engineered to the specific building or process line, cab or cab-free remote-controlled operation, and explosion-proof or corrosion-resistant packages for special environments.
