LD Model Single Girder Overhead Crane

Core Components: Gearbox, Motor, Gear

Place of Origin: Henan, China

Warranty: 1 Year

Weight (KG): 10000 kg

Video outgoing-inspection: Provided

Machinery Test Report: Provided

Selling Units: Single item

Single package size: 600X300X300 cm

Single gross weight: 200.000 kg

Excellent choice. The Single Girder Overhead Crane is the most common and cost-effective type of overhead crane, ideal for light to medium-duty applications (typically up to 20 tons, though designs can vary).

Here is a detailed breakdown of its key components, categorized by their functional groups:

1. Bridge Structure (The Main Traveling Frame)

Main Girder (Single): The primary horizontal beam that spans the width of the bay. It is usually a rolled steel I-beam or a fabricated box-type beam. It supports the hoist and trolley and must resist bending.

End Trucks (x2): The steel structures located at each end of the main girder. They house the wheels, drive motors, and mechanisms for the bridge travel.

End Carriage: Another term for the end truck assembly.

2. Hoist and Trolley Unit (The Lifting & Traversing Mechanism)

Electric Hoist: The device that performs the actual lifting and lowering. For single girder cranes, this is typically a wire rope hoist or, for lighter capacities, a chain hoist.

Trolley Frame: The frame that carries the hoist. It moves laterally (cross travel) along the bottom flange of the main girder.

Trolley Drive: The motorized system (often a simple electric motor with a gearbox driving wheels) that moves the trolley back and forth along the girder.

Hook Block: The assembly at the end of the hoist's wire rope, containing the hook, sheaves (pulleys), and block body.

3. Motion Drives (The Propulsion Systems)

Bridge Drive: The system that moves the entire crane along the runway beams. It consists of:

Bridge Drive Motor(s): Usually one motor per end truck, synchronized to run together.

Bridge Drive Wheels: The wheels on the end trucks that ride on the runway rails.

Gearboxes/Reducers: To reduce motor speed and increase torque.

Trolley Drive: As mentioned above, the motor and wheels that move the trolley.

Hoist Drive: The motor, brake, and gearing inside the hoist unit for lifting.

 

4. Runway System (The Crane's "Track")

Runway Beams: The fixed horizontal beams, usually attached to the building's columns or a separate support structure, on which the crane travels.

Runway Rails: The steel rails (often standard crane rails like AISC or flat bars) mounted on top of the runway beams. The crane's bridge drive wheels run on these.

Crane Stops/Bumpers: Physical stops installed at the ends of the runway to prevent the crane from over-traveling.

5. Electrical System (The "Nervous System")

Main Power Supply: Typically via Festoon System (cable carried on a trolley system) or Conductor Bar/Enclosed Rails (rigid bars with a sliding collector).

Control System:

Operator's Pendant/Radio Control: The most common control methods. A pendant is a hanging control station with buttons for all motions (Up/Down, Left/Right, Forward/Backward). Radio control offers wireless operation.

Control Panel/Enclosure: Houses contactors, variable frequency drives (VFDs for smooth control), overload protection, and PLCs (for advanced cranes).

Limit Switches: Critical safety devices that automatically cut power to a motion to prevent over-travel (hook upper/lower limit, bridge and trolley end limits).

Cabin (Optional): For very frequent or heavy-duty use, an operator's cabin may be suspended from the bridge, containing all controls and seats.

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6. Safety Components (Mandatory for Safe Operation)

Brakes: Found on all three motions-hoist (primary holding brake), bridge, and trolley.

Overload Limit Device: Prevents the hoist from lifting loads beyond its rated capacity.

Anti-Collision Systems: Sensors to prevent multiple cranes on the same runway from colliding.

Warning Devices: Lights and audible alarms (buzzers/horns).

Emergency Stop Buttons: Located on the pendant and other key locations.

Typical "LD Model" Nomenclature

In many catalogs (especially from international manufacturers), "LD" often stands for a standard duty, electrically-driven, single girder overhead crane.

L might denote the type (e.g., "Lifting" or a series code).

D might denote the drive configuration or duty class.
Common variants include LDA (standard single girder), LDP (low headroom single girder with a hoist integrated into the girder web), and LDT (using a European-style wire rope hoist).

Sketch

 

Main technical

 

Excellent question. The LD (European designation often meaning "Light Duty") single girder overhead crane is a workhorse in many industrial settings for very good reasons. Here are its key advantages, broken down by category:

1. Cost-Effectiveness (The Biggest Advantage)

Lower Initial Investment: Requires less steel (one girder vs. two) and a simpler hoist/trolley system, making it significantly cheaper to purchase and install than a double girder crane.

Reduced Structural Costs: Lighter weight means the existing building structure (runway beams/columns) often requires less reinforcement, saving on building costs.

Lower Maintenance Costs: Simpler design with fewer components translates to lower long-term maintenance and repair expenses.

2. Design Simplicity & Efficiency

Clean, Compact Design: The hoist trolley runs on the bottom flange of the single box girder. This creates a lower headroom requirement (the distance from the hook to the runway beam).

Excellent Hook Coverage: The trolley can travel the full length of the girder, and the girder itself travels the length of the runway, providing excellent service coverage for the bay.

Ideal for Standard Applications: Perfectly suited for straightforward lifting, transporting, and positioning of loads without complex requirements.

3. Performance & Operational Advantages

Faster Speeds: Due to the lighter overall weight, LD single girder cranes can often achieve higher travel speeds (both for the hoist trolley and the bridge) than heavier double girder cranes, improving cycle times for light to medium-duty tasks.

Easier Installation: The components are lighter and simpler to assemble, reducing installation time and complexity.

Energy Efficiency: Less mass to move means lower power consumption during operation.

4. Space-Saving

Lower Headroom: As mentioned, this is critical in buildings with height limitations. It maximizes usable lift height under the crane.

Reduced Wheel Load: The lighter crane exerts less force on the runway beams and supporting columns, which can be a major advantage in older facilities.

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Ideal Applications for an LD Single Girder Crane:

Workshops, warehouses, and assembly lines.

Handling raw materials, finished goods, or machine parts.

Frequent but relatively light-duty material handling (e.g., several lifts per hour).

Typical Capacity Range: Up to 20 metric tons (with spans usually up to ~30 meters, though this varies by manufacturer and design).

Duty Cycle: Suited for Class A1 (Standby/Infrequent use) to A3 (Light service) under FEM/ISO standards.

 

Primary Applications

The LD crane is the workhorse of light industry and is ubiquitous in settings where efficient, reliable, and relatively inexpensive overhead lifting is needed.

1. Manufacturing & Assembly Plants

Machine Shops: Moving raw materials (steel bars, plates), positioning workpieces on lathes, milling machines, and CNC centers.

Automotive Parts Manufacturing: Handling engines, axles, and sub-assemblies along production lines.

Appliance Manufacturing: Moving components like metal casings, compressors, etc.

2. Warehousing & Logistics Centers

Loading/Unloading Bays: Transferring goods from trucks to storage areas.

Storage/Retrieval: Handling palletized goods, machinery parts, or packaged products. Often used in conjunction with forklifts for dense storage layouts.

3. Maintenance & Repair Facilities

Power & Utility: For maintenance of pumps, turbines, and transformers.

Vehicle Repair: Lifting engines, bus bodies, or agricultural equipment in repair bays.

4. Light Fabrication & Workshops

Steel Service Centers: Handling and shearing metal sheets, bars, and tubes.

Welding Shops: Positioning and flipping large weldments.

5. Paper, Printing, and Packaging Industries

Handling rolls of paper, large reels, and heavy packaging machinery.

 

Here is a detailed production procedure for an LD Model Single Girder Overhead Crane:

1. Design & Engineering Phase

Customer requirements analysis: Capacity, span, lifting height, duty cycle, control mode, etc.

Structural design:

Main girder (box-type or I-beam)

End carriages

Hoist trolley

Electrical system design: Motor selection, control panel, wiring, safety devices

Drawings creation: Manufacturing, assembly, electrical diagrams

Material & component specification

2. Material Procurement & Inspection

Steel materials: Plates, profiles (Q235B/Q345B)

Mechanical components: Wheels, axles, bearings, gears, shafts

Electrical components: Motors, gearboxes, brakes, limit switches, controllers, cable reels

Hoist unit: Electric wire rope hoist (standard LD model hoist)

Inspection: Material certificates, dimensional checks, quality verification

3. Fabrication of Main Components

A. Main Girder Fabrication

Cutting: CNC plasma/oxy-fuel cutting of steel plates

Pre-assembly welding: Web plates, top/bottom flanges

Full welding: Automatic/submerged arc welding for critical joints

Stress relieving (if required for larger spans)

Machining: Drilling holes for connections, runway rail mounting

Straightening & inspection: Camber pre-set, dimensional accuracy check

B. End Carriage Fabrication

Frame assembly: Welding of side frames, cross members

Wheel assembly: Mounting wheels, axles, bearings

Buffer & bumper installation

Drive unit mounting: For motorized end carriages

C. Hoist Trolley Fabrication

Frame assembly

Wheel mounting

Hoist installation: Mounting of standard LD hoist unit

Electrical connections

4. Surface Treatment & Painting

Surface preparation: Shot blasting (SA 2.5 grade)

Primer coating: Anti-rust primer

Intermediate & top coats: Industrial enamel (standard colors or customer specification)

Marking & stenciling: Capacity, serial number, warnings

5. Electrical System Assembly

Control panel assembly: Contactors, overload relays, circuit breakers

Cable festoon system or conductor bar installation

Limit switches: End limit switches, hoist upper/lower limits

Push button pendant assembly (for floor control)

Cabin assembly (for cab-operated cranes)

6. Pre-assembly & Testing

Trial assembly in factory:

Main girder + end carriage assembly

Hoist trolley installation

Electrical wiring connection

Factory testing:

No-load test: Travel in both directions, hoist operation

Load test: 25%, 75%, 100%, 125% of rated capacity

Safety device testing: Limit switches, emergency stop

Insulation resistance test

Noise level measurement

7. Dismantling & Packaging

Careful dismantling into transportable sections

Protection of machined surfaces, electrical components

Weatherproof packaging for sea/land transportation

Documentation package included: Manuals, certificates, drawings

8. Quality Control Points (Throughout Process)

Material inspection certificates

Weld quality (visual, NDT if required)

Dimensional accuracy at each stage

Electrical component testing

Load testing certification

Final inspection report

9. Documentation & Certification

Manufacturer's data report

Test certificates (factory load test)

Operation & maintenance manuals

Electrical diagrams

Part lists & spare parts recommendations

CE certification (if for European market) or other local certifications

10. Installation & Commissioning (at customer site)

Erection by trained technicians

Alignment of runway rails

Reassembly & connection

Final testing & commissioning

Customer training

Final inspection report

Workshop view:

The company has installed an intelligent equipment management platform, and has installed 310 sets (sets) of handling and welding robots. After the completion of the plan, there will be more than 500 sets (sets), and the equipment networking rate will reach 95%. 32 welding lines have been put into use, 50 are planned to be installed, and the automation rate of the entire product line has reached 85%.