Qd Hook Double Girder Overhead Crane

Key Features of QD Hook Double Girder Overhead Crane:

Double Girder Design

Consists of two main girders for enhanced strength and stability.

Higher lifting capacity compared to single girder cranes (typically 5T to 550T).

QD (Hook) Mechanism

Equipped with a hook lifting mechanism for general-purpose material handling.

Can be customized with grab buckets, magnets, or other attachments for specialized applications.

Hoisting Mechanism

Uses an electric hoist (usually European-style hoist or traditional trolley hoist).

Available in single or double hoist configurations for different lifting needs.

Working Class & Duty Cycle

Designed for A5 to A7 duty class (moderate to heavy-duty cycles).

Suitable for frequent lifting operations in industrial environments.

Control System

Operated via pendant control (push-button pendant) or radio remote control.

Can be integrated with variable frequency drives (VFD) for smooth acceleration and deceleration.

Travel Mechanism

Crab (trolley) travel along the girders.

Bridge travel along the runway beams (end carriages with wheels).

Safety Features

Overload protection (load limiter).

Limit switches for hoisting and travel motions.

Emergency stop button.

Anti-collision system (for multiple cranes in the same bay).

 

Feature	QD Double Girder Crane	Single Girder Crane
Capacity	5T–550T+	1T–20T
Span	Up to 35m+	Up to 25m
Duty Class	A5–A7 (Heavy Duty)	A3–A5 (Light/Medium)
Hook Height	Higher (better vertical space use)	Lower
Stability	More rigid, less deflection	More flexible
Cost	Higher initial cost	More economical
Applications	Heavy industries, steel, power plants	Workshops, warehouses, light industry

 

Technical Specifications (Standard Model Example)

Lifting Capacity 5T - 550T
Span Length 10.5m - 35m (customizable)
Lifting Height 6m - 30m (adjustable)
Work Duty A5, A6, A7
Operating Speed
Hoisting: 0.5-8 m/min (adjustable)
Trolley Travel: 5-30 m/min
Crane Travel: 10-60 m/min
Power Supply 3-phase, 380V/50Hz (or as per local standards)

 

 

A QD Hook Double Girder Overhead Crane consists of several key mechanical and electrical components that work together to ensure efficient and safe lifting operations. Below is a detailed breakdown of its major components:

 

1. Bridge Girders (Main Beams)

Function: The primary load-bearing structure that spans the width of the crane bay.

Material: Typically made of box-type welded steel (or truss-type for very heavy loads).

Features:

Double girders provide higher strength than single girders.

Designed to resist bending and torsional forces.

2. End Carriages (End Trucks)

Function: Support the bridge girders and facilitate crane movement along the runway rails.

Components:

Wheels (usually 4 or more, made of forged steel or polyurethane).

Buffers (Bumpers) – Absorb impact when the crane reaches travel limits.

Drive Motors & Gearboxes – Power the crane's longitudinal movement.

3. Hoisting Mechanism

Function: Lifts and lowers the load.

Components:

Electric Hoist (Main Hoist & Auxiliary Hoist, if applicable) – Includes motor, drum, wire rope, and hook.

Wire Rope & Sheaves – Transmit lifting force.

Hook Block – Connects to the load (can be single or double hook).

Brake System – Prevents load slippage.

4. Trolley (Crab Unit)

Function: Moves horizontally along the bridge girders to position the load.

Components:

Trolley Frame – Supports the hoist and drive system.

Trolley Wheels & Rails – Allow smooth travel along girders.

Drive Motor & Gearbox – Powers trolley movement.

5. Runway System

Function: Provides the track for the crane's movement.

Components:

Runway Beams – Installed on building columns or freestanding supports.

Rail Tracks – Usually P38, QU70, QU80, or QU120 (depending on load capacity).

Rail Clamps – Secure the crane in place when not in use.

6. Electrical System

Function: Controls crane operations.

Components:

Control Panel (Electrical Cabinet) – Houses contactors, relays, and PLC (if automated).

Pendant Control / Radio Remote – Operator interface for manual control.

Limit Switches – Prevent over-travel of hoist and trolley.

Power Supply System – Festoon system (cable reels) or busbar (energy rail).

Variable Frequency Drives (VFDs) – For smooth speed control (optional).

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7. Safety Devices

Function: Ensures safe operation.

Components:

Overload Limiter – Prevents lifting beyond rated capacity.

Emergency Stop Button – Instantly cuts power.

Anti-Collision System – Used when multiple cranes operate in the same bay.

Warning Lights & Horn – Alerts workers during movement.

8. Optional Accessories

Magnetic Lifter / Grab Bucket – For specialized material handling.

Weighing System – Measures load weight in real-time.

Laser Positioning System – For precise load placement.

Crane Camera System – Improves visibility for the operator.

 

12.Sketch

Main technical

 

 

The QD (General Duty) Hook Double Girder Overhead Crane is a robust and versatile lifting solution designed for heavy-duty industrial applications. Here are its key advantages:

1. Higher Lifting Capacity

Supports 5T to 550T+, making it ideal for heavy loads (compared to single girder cranes, which typically max out at 20T).

Double girder design distributes weight more evenly, reducing stress on components.

2. Greater Span & Stability

Can handle longer spans (10m to 35m+) without deflection, suitable for wide workshops.

More rigid and stable than single girder cranes, minimizing sway during lifting.

3. Higher Duty Class (A5-A7)

Built for moderate to heavy-duty cycles, making it suitable for frequent use in steel plants, foundries, and heavy industries.

Longer service life due to durable construction.

4. Flexible Hoisting Configurations

Can be equipped with dual hoists (main + auxiliary) for multi-lifting operations.

Compatible with hooks, grabs, magnets, and other attachments for specialized handling.

5. Better Hook Height Utilization

The low headroom design (if required) maximizes vertical lifting space, ideal for facilities with height restrictions.

6. Smoother & More Precise Control

Variable Frequency Drive (VFD) options allow for soft starts/stops, reducing load swing.

Radio remote & pendant controls improve operator safety and precision.

7. Enhanced Safety Features

Overload limiter prevents exceeding capacity.

Emergency stop, limit switches, and anti-collision systems improve workplace safety.

8. Customizable for Special Environments

Available in explosion-proof, high-temperature, or corrosion-resistant variants for harsh conditions.

Applications of QD Hook Double Girder Overhead Crane

This crane is widely used in industries requiring heavy lifting, high precision, and durability. Common applications include:

1. Steel & Metal Industry

Handling steel coils, slabs, ingots, and molds in rolling mills and foundries.

Loading/unloading heavy metal sheets in fabrication shops.

2. Power Plants & Heavy Machinery

Lifting turbines, generators, and transformers.

Maintenance of boilers and large mechanical parts.

3. Shipbuilding & Ports

Assembling ship hulls and large components.

Loading/unloading heavy cargo in docks.

4. Mining & Cement Industry

Moving raw materials, crushers, and kiln parts.

Handling bulk materials with grab attachments.

5. Automotive & Aerospace

Lifting engine blocks, fuselage sections, and heavy molds.

Used in assembly lines for large vehicle components.

6. Warehousing & Logistics

Heavy-duty warehouse material handling (e.g., machinery, large containers).

Railway workshops for lifting locomotives and rail cars.

7. Paper & Chemical Industry

Handling large rolls of paper in mills.

Moving heavy reactors and storage tanks in chemical plants.

 

 

1. Design & Engineering
Confirm customer requirements (capacity, span, height, working environment).

Create detailed structural and mechanical design using CAD and FEM analysis.

Select appropriate materials, components, and safety devices.

2. Material Procurement
Purchase high-quality steel plates, sections, motors, electrical parts, and control systems.

Verify materials comply with standards and specifications.

3. Cutting & Preparation
Steel plates and profiles are cut using CNC plasma or laser cutting machines.

Prepare steel parts for welding (edge cleaning, beveling).

4. Welding & Assembly of Main Components
Weld main girders, end carriages, and trolley frames using certified welding procedures.

Perform initial assembly of components to check fit and alignment.

5. Heat Treatment & Stress Relieving (if required)
Apply heat treatment to reduce welding stress and improve mechanical properties.

6. Machining
Machine key parts such as wheel seats, bearing housings, and motor mounting surfaces.

Ensure precision for smooth operation.

7. Surface Treatment
Clean steel surfaces (sandblasting).

Apply primer and high-quality paint for corrosion protection.

8. Assembly of Mechanical & Electrical Systems
Install motors, brakes, hoists, wheels, limit switches, and safety devices.

Assemble electrical panels and wiring harnesses.

9. Testing & Quality Inspection
Perform load testing (usually 125% to 150% of rated capacity).

Check operational functions: hoisting, traveling, limit switches, emergency stops.

Inspect welds, paint, and mechanical clearances.

10. Final Adjustments & Packaging
Make necessary adjustments based on testing results.

Pack crane components carefully for transport.

11. Delivery & Installation
Ship crane to customer site.

Install and commission crane on-site.

Provide operator training and maintenance guidance.

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%.