QD Type Overhead Crane

What is a QD Type Overhead Crane?

A QD Type Overhead Crane is a specific and very common classification of a heavy-duty, electric overhead traveling (EOT) crane. The "QD" designation originates from Chinese industrial standards (JB/T) and stands for "Electric (Dian) Hoist (Qi)" or is often interpreted as "General Duty" bridge crane. It is a versatile, robust, and widely used crane designed for reliable performance in various industrial applications.

 

Advantages of QD Type Overhead Cranes

Proven Reliability: A mature, standardized design known for its durability and low maintenance needs.

Excellent Value: Offers a great balance of performance, features, and cost for general industrial use.

Versatility: Suitable for a very wide range of applications, from manufacturing and assembly to warehousing.

Strong Performance: The M5 duty cycle is sufficient for the vast majority of factory and workshop lifting tasks.

Good Load Stability: The double girder design ensures smooth and stable load movement.

 

Comparison: QD vs. Other Overhead Cranes

Feature	QD Type (Heavy Duty)	QL Type (Light Duty)	QC Type (Severe Duty)
Duty Cycle	M5 (Heavy Duty)	M3/M4 (Light/Medium)	M6/M7 (Severe/Very Severe)
Typical Use	General Factory & Workshop	Light Manufacturing	Steel Mills, Foundries
Girder Design	Double Girder	Single/Double Girder	Double Girder
Robustness	High	Moderate	Very High
Cost	Moderate	Lower	Higher

Conclusion: The QD Type Overhead Crane is the definitive standard for heavy-duty lifting in general industry. It is not a light-duty machine, nor is it built for the extreme punishment of a steel mill. It occupies the essential middle ground, providing robust, reliable, and efficient lifting power for the countless tasks that keep factories and workshops running. Its widespread use is a testament to its effective and practical design.

 

Core Components：Bearing, Gearbox, Motor, Pump

Place of Origin：Henan, China

Warranty：1 Year

Weight (KG)：2000 kg

Video outgoing-inspection：Provided

Machinery Test Report：Provided

Design：Double beam

Effectiveness：high efficiency

Operating speed：High speed operation

Stability：Anti-swing function

Color：Optional

Power Source：110V/220V/230V/380V/440V,customized

Span：7.5-31.5m

Here is a detailed breakdown of the components of a QD Type Overhead Crane.

 

1. Primary Structural System (The Framework)

Double Main Girders: The primary horizontal beams that form the bridge.

Box Girders: Fabricated from steel plate for optimal strength-to-weight ratio and rigidity. This is the standard for QD cranes.

End Trucks: The structures at each end of the bridge that house the wheels and drive mechanisms for moving the entire crane along the runway.

Wheels: Forged or cast steel wheels with hardened treads.

Axles: To support the wheels and transmit drive power.

Runway System:

Runway Beams: Heavy I-beams or box sections supported by the building columns.

Running Rails: Steel rails mounted on top of the runway beams.

Crane Buffers: Shock-absorbing devices at the ends of the runway.

2. Lifting & Travel System (The Workhorse)

Main Hoist Unit:

Hoist Motor: Electric motor providing lifting power.

Gearbox: Reduces motor speed to increase torque.

Wire Rope Drum: Spools the wire rope.

Brakes: Primary and secondary braking systems.

Trolley Assembly:

Trolley Frame: Supports the hoist unit.

Trolley Wheels & Drive: Wheels that run on rails on top of the main girders, with a separate drive motor for transverse movement.

 

Auxiliary Hoist: An optional, smaller, faster hoist on the same trolley for lighter loads.

Hook Block: The assembly that holds the hook, often with multiple sheaves for mechanical advantage.

Bridge Travel Drives:

Drive Motors: Motors mounted on the end trucks to propel the entire crane.

Wheels: Flanged wheels that run on the runway rails.

3. Power, Control & Motion Systems (The Nerves)

Power Supply System:

Conductor Bar System: Enclosed power bars running parallel to the runway.

Festoon System: A trolley and track system that carries flexible power cables.

Control Interface:

Pendant Station: A hanging push-button control box.

Radio Remote Control: Wireless operation for operator mobility.

Control Panel:

Contactors and Relays: For power distribution and control.

Overload Relays: To protect motors from overcurrent.

Variable Frequency Drives (VFDs): Often included for smooth speed control.

4. Critical Safety Systems (The Lifeline)

Overload Limiter: A mandatory device that prevents the hoist from lifting beyond its rated capacity.

Limit Switches:

Hoist Upper/Lower Limit: Prevents over-hoisting or over-lowering.

Travel Limits: Stops crane and trolley at runway ends.

Braking Systems:

Hoist Brake: Automatically holds the load.

Travel Brakes: On bridge and trolley drive motors.

Emergency Stop Buttons: Located at various points on the crane and pendant.

Warning Device: Horn or buzzer to alert personnel.

Summary: Key Features of a QD Type Crane

Component	QD Type Characteristic
Girders	Double Box Girders for strength and rigidity
Hoist	Industrial wire rope hoist rated for M5 duty
Trolley	Top-running for maximum hook height
Control	Pendant or radio remote standard
Safety	Overload limiter and limit switches mandatory

Conclusion: Every component of a QD Type Overhead Crane is engineered for reliability, safety, and efficient performance in a general heavy-duty industrial environment. The integration of robust structural elements with standardized, proven components makes it a versatile and dependable solution for a wide range of material handling applications.

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Main technical

 

 

Advantages of QD Type Overhead Crane

QD Type Overhead Cranes offer a powerful combination of reliability, versatility, and value, making them the standard choice for general heavy-duty industrial lifting.

 

1. Proven Reliability and Durability

Robust Construction: Built with double box girders and industrial-grade components designed for M5 (Heavy Duty) service, ensuring long-term reliability.

Long Service Life: Engineered to withstand regular, frequent use in industrial environments with minimal downtime.

Consistent Performance: Maintains stable operation even when handling loads close to its rated capacity.

2. Excellent Value and Cost-Effectiveness

Optimal Investment: Offers the best balance between performance features and cost for general industrial applications.

Lower Operating Costs: Simple design and standardized components reduce maintenance requirements and costs.

Energy Efficient: Modern electrical systems and efficient motor designs minimize power consumption.

3. Versatility and Adaptability

Wide Application Range: Suitable for various industries and lifting tasks.

Flexible Configurations: Can be customized with different spans, lifting heights, and capacities.

Multiple Control Options: Available with pendant control or radio remote operation.

Attachment Compatibility: Can be equipped with various lifting attachments.

4. Ease of Operation and Maintenance

User-Friendly Controls: Simple and intuitive operation requiring minimal specialized training.

Accessible Components: Designed for easy maintenance and service access.

Standardized Parts: Uses commonly available components, reducing spare part costs and downtime.

5. Safety and Compliance

Comprehensive Safety Features: Includes overload limiter, limit switches, emergency stops, and warning devices.

Regulatory Compliance: Built to meet international safety standards and regulations.

Stable Operation: Double girder design provides excellent load stability and control.

 

Applications of QD Type Overhead Crane

The QD Type Overhead Crane is the workhorse of general industry, serving numerous sectors with reliable material handling solutions.

 

1. Manufacturing and Assembly Plants

Production Lines: Moving raw materials and components between workstations.

Assembly Operations: Handling large sub-assemblies and finished products.

Machine Loading/Unloading: Positioning heavy parts in machining centers.

2. Warehousing and Logistics Centers

Heavy Item Handling: Moving large or heavy palletized goods.

Loading Docks: Transferring materials to and from trucks.

Storage Operations: Placing and retrieving items from high-level storage.

3. Steel Service and Metalworking

Material Handling: Moving steel plates, beams, and other metal products.

Fabrication Shops: Handling raw materials and finished fabrications.

Service Centers: Processing and storing metal inventory.

4. Power Plants and Utilities

Maintenance Operations: Handling turbines, generators, and transformers.

Equipment Service: Installing and maintaining heavy equipment.

Fuel Handling: Moving maintenance materials and components.

5. Maintenance and Repair Facilities

Equipment Maintenance: Lifting heavy machinery for service and repair.

Component Replacement: Handling large components during maintenance.

Workshop Operations: General material handling in repair shops.

 

The production process for a QD Type Overhead Crane is a systematic and quality-controlled procedure that ensures reliability and safety for industrial use.

Here is a detailed breakdown of the production process.

 

Stage 1: Design & Engineering

This stage defines the crane's specifications and creates the blueprint for production.

Client Requirements Analysis: Reviewing key parameters: capacity, span, lifting height, duty cycle (M5), and operational needs.

Structural & Mechanical Design:

Structural Analysis: Calculating loads and stresses to determine girder size (typically box girders) and component specifications.

Component Selection: Specifying the hoist, trolley, drive motors, wheels, and gearboxes from trusted suppliers.

Electrical Design: Creating schematics for power supply, motor controls, and safety circuits.

Bill of Materials (BOM) Creation: Listing all raw materials and purchased components.

 

Stage 2: Material Procurement & Preparation

Procurement: Sourcing certified steel plates, beams, and purchased components (hoists, motors, electrical gear).

Material Preparation: Steel components are cut to length using saws or CNC plasma cutters. Plates are cut to profile for box girders.

 

Stage 3: Structural Fabrication & Assembly

This is where the crane's robust frame is built.

Girder Fabrication:

Box Girder Construction: For QD cranes, girders are fabricated from steel plate. Web and flange plates are cut, and internal stiffeners are welded in.

Process: Components are fit in jigs to ensure straightness and correct geometry.

Welding: Critical welds are performed using Automated Submerged Arc Welding (SAW) for long, strong seams. All welds are performed by certified welders.

Stress Relieving (for larger cranes): The completed girders may be heated in a furnace to relieve internal stresses from welding.

Machining: The girder ends and surfaces where the trolley rails will be mounted are machined to ensure perfect alignment.

 

Stage 4: Mechanical Assembly

The structural frame is integrated with the mechanical systems.

End Truck Assembly: The end trucks are built, housing the wheels, axles, and bridge travel drive assemblies.

Bridge Assembly: The two main girders are connected to the end trucks to form the complete bridge structure.

Trolley Assembly: The trolley frame is built, and wheels are attached. The main hoist unit is then mounted and aligned onto the trolley frame.

Rail Installation: The rails for the trolley are installed and aligned on top of the main girders.

 

Stage 5: Electrical & Control System Installation

The crane's control and power systems are installed.

Cable Installation: Power and control cables are run along the crane structure in protective conduits or cable trays.

Panel Installation: Main control panels, housing contactors, overload relays, and often Variable Frequency Drives (VFDs), are mounted on the bridge.

Power Supply Setup: Installation of the conductor bar system or festoon system for power delivery.

Safety Devices: Installing and wiring limit switches, emergency stops, and the overload protection device.

 

Stage 6: Works Testing & Inspection (FAT - Factory Acceptance Test)

The fully assembled crane is tested to ensure it meets all specifications and safety standards.

Visual & Dimensional Inspection: Checking for workmanship, paint quality, and verifying all critical dimensions (span, wheelbase).

No-Load Test: Operating all motions (hoist, trolley, bridge) without a load to check for smooth operation and abnormal noise.

Load Testing:

Static Load Test: Lifting a test load of 125% of the rated capacity and holding it to verify structural integrity and brake holding capacity.

Dynamic Load Test: Lifting 110% of the rated capacity and running it through all motions to ensure performance under working conditions.

Safety Function Test: Verifying the operation of all limit switches, brakes, E-stops, and the overload limiter.

 

Stage 7: Dismantling, Painting & Packaging

Dismantling: The crane is carefully disassembled into transportable modules (girders, end trucks, trolley).

Final Painting: A primer and topcoat are applied for corrosion protection.

Packaging: Components are securely packaged, with special attention to protecting machined surfaces and electrical components.

 

Stage 8: Site Installation & Commissioning (SAT - Site Acceptance Test)

Site Erection: The crane is reassembled on the customer's runway.

Final Connections: Electrical power is connected, and final checks are made.

Site Commissioning & SAT: The crane undergoes a final operational test in its actual working environment.

Operator Training: The customer's operators are trained on safe and efficient use.

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%.