Rolling Bridge Crane

 

1.A rolling bridge crane is a type of bridge crane widely used in industrial applications for lifting and moving heavy loads in factories, warehouses, and outdoor environments. This crane type consists of two parallel girders (beams) that run along a runway track, supported by end carriages. The hoist and trolley system, which moves along the top of the girders, is capable of lifting large loads with high precision.rolling bridge cranes are known for their robust construction, enhanced load-carrying capacity, and superior lifting height compared to single girder cranes, making them ideal for heavy-duty operations.

2.The crane features two parallel beams (girders), which provide greater support and distribute the load more evenly, allowing the crane to handle higher capacities and larger spans.The girder design improves the crane's stability and durability, making it suitable for demanding lifting tasks.Double girder cranes are capable of handling heavier loads compared to single girder cranes. Capacities typically range from 5 tons to over 100 tons, depending on the application.Their strong structure allows them to lift large and bulky items such as machinery, large steel structures, and heavy equipment.

3.The use of two girders allows for a wider span (the distance between the crane rails), making double girder cranes ideal for larger facilities and applications that require long travel distances for material handling.With the ability to span longer distances, double girder cranes can cover larger operational areas, reducing the need for multiple smaller cranes.These cranes typically offer greater lifting height than single girder designs. This is achieved by mounting the hoist and trolley system on top of the girders, allowing for more vertical lifting distance.

Core Components：Engine, Bearing, Gearbox, Motor, Pressure vessel

Place of Origin：Henan, China

Warranty：1 Year

Weight (KG)：10000 kg

Video outgoing-inspection：Provided

Machinery Test Report：Provided

Power supply：3 Phase AC 380V 50HZ

Control method：remote Control, pendent control,cabin control

Lifting mechanism：Electric Hoist or trolley

Crane type：Double Girder

Travelling speed：20m/min,30m/min

Lifting speed：0.8/5m/min 1/6.3m/min

Work Duty：A4-A7

Crane Feature：Widely

Pictures & Components

 

 

1.Main beam

1)Load Capacity:

The main beam is designed to handle the maximum rated load capacity of the crane. The thickness of the beam, the type of material used, and the type of cross-section are all chosen based on the weight the rolling bridge crane is expected to lift. Higher capacity cranes typically use more robust, thicker beams to ensure safety and structural integrity.

2)Span and Lifting Height:

The length of the main beam determines the span of the rolling bridge crane, i.e., the distance between the two runway rails. The longer the span, the more robust the girder needs to be to maintain its structural integrity and prevent sagging.The height of the girder is also important for determining the lifting height of the crane. A higher girder can allow for greater lifting height.

The main beam must be designed to support not only the dead weight of the crane and its components but also the dynamic forces generated when lifting and moving heavy loads.Engineers calculate the expected load distribution and use steel reinforcements or strengthening ribs to ensure that the beam can withstand the stresses encountered during operation.

Lifting System

1)Hoisting the Load:

The operator engages the hoist via the control system (remote control, pendant, or cabin). The hoist motor begins to rotate, winding the wire rope or load chain around the drum.

As the rope or chain is wound onto the drum, the load hook or other lifting attachment (such as a grab or spreader bar) is lifted. The hoist provides the force needed to raise the load vertically.

2)Traveling the Trolley:

The trolley moves horizontally along the rolling bridge crane's main girders via the trolley motors. This motion allows the hoist to move across the full span of the crane to position the load at the desired location.

3)Lifting and Lowering Movements:

The combination of hoist and trolley allows the crane to lift, lower, and horizontally move the load within the crane's span.Depending on the load and operational requirements, the operator can control the lifting speed, trolley travel speed, and positioning of the load. Advanced variable frequency drives (VFDs) provide precise control of these functions.

Controlling the Load:

The crane operator can fine-tune the position of the load by using the control system, which could be a pendant control, radio remote, or a cabin operator panel.

3.End carriage

1)Support the Crane Structure:

The end carriage supports the main girders of the rolling bridge crane, which carry the lifting system (hoist and trolley). It ensures that the load is evenly distributed across the crane's wheels during movement.

2)Facilitate Horizontal Movement:

The primary function of the end carriage is to enable the crane to move along the runway rails. This movement is crucial for positioning the crane over the load or for transferring the load to another part of the facility.

3)Stability and Safety:

The end carriage helps to ensure the crane's stability while in motion by supporting the weight of the crane and the load. It plays a crucial role in preventing tilting, swaying, or wobbling during travel.

Shock absorbers or cushioning systems may be included in the end carriage design to absorb shocks and vibrations, improving safety and comfort during operation.

4.Crane travelling mechanism

The crane traveling mechanism operates in a simple, yet precise manner. Here's a step-by-step breakdown of how it works:

1)Motor Activation:

When the crane operator activates the travel controls, the motor on one of the end carriages starts rotating. This motor is connected to the wheels through a gearbox.

The geared drive system converts the rotational movement of the motor into the motion required to move the crane along the runway.

2)Wheel Movement:

As the motor turns, it drives the wheels on the end carriage. The wheels, in turn, roll along the runway rails, allowing the crane to move horizontally.

The wheels are designed to minimize friction and wear, providing smooth movement and reducing the energy required for travel.

3)Controlled Travel:

The control system (pendant, remote, or cabin controls) allows the operator to adjust the speed and direction of the crane's travel. With variable frequency drives (VFDs), the operator can set the crane's speed smoothly across a range, starting slowly and accelerating to full speed as needed.

The crane can be stopped or reversed at any time using the control system, allowing the operator to adjust the crane's position accurately.

4)Braking:

When the operator wants to stop the crane, the braking system is engaged. The brakes slow down the motion of the wheels, bringing the crane to a smooth stop.

In most cases, the crane's motor and brakes work together, with the motor reversing its direction to slow the crane down gradually (also known as dynamic braking).

5)Load Stability:

The end carriages and wheels support the entire crane and load during travel. The weight of the crane and load is evenly distributed across the wheels, ensuring stable movement.

The wheels' alignment with the runway rails ensures that the crane maintains its course and does not derail during operation

5.Trolley travelling mechanism

Maintenance of the Trolley Traveling Mechanism

1)Wheel and Rail Inspection:

The wheels on the trolley should be inspected regularly for wear, cracks, and misalignment. Worn wheels can cause the trolley to move unevenly and lead to excessive wear on the rails.

The girder rails should be checked for alignment and wear. Misaligned or damaged rails can lead to erratic trolley movement or even derailment.

2)Lubrication:

The wheel bearings and gears in the trolley traveling mechanism should be regularly lubricated to reduce friction and wear. Proper lubrication extends the lifespan of the components and ensures smooth operation.

3)Motor and Gearbox Maintenance:

The motor and gearbox should be inspected for signs of wear or damage. This includes checking motor brushes, oil levels, and the condition of the gearbox components.

4)Brake System Checks:

The braking system should be inspected periodically to ensure it is working correctly. This includes checking brake pads, hydraulic fluids, and ensuring that the brake system engages smoothly.

6.Crane wheel

1)Load Support:

The crane wheels are designed to support the entire weight of the crane, including the hoist, main girder, and the load being lifted. Depending on the crane's design and capacity, the wheels may also support additional systems like the trolley or bridge.

The wheels help distribute the load evenly along the runway rails, ensuring the crane operates with stability and balance.

2)Horizontal Movement:

The primary function of the crane wheels is to allow the crane to travel along the runway rails. As the end carriages move along the rails, the wheels roll and provide the necessary motion for the crane to travel horizontally.

The wheels must provide smooth, uninterrupted movement to avoid any jerky motion or strain on other components like the drive motors or gear systems.

7.Crane Hook

1)Lifting and Lowering Loads:

The crane hook is designed to engage with the load via slings, chains, or other rigging equipment, allowing it to lift and lower the load with the hoist mechanism.

The hook provides the connection point between the crane's lifting system and the load, transferring the weight of the load to the crane's lifting capacity.

2)Load Positioning:

The hook allows for the precise positioning of the load as the crane moves. It can be used to lift and lower the load to a desired height or move it horizontally across the crane's span.

In cranes with swivel hooks, the hook can rotate, which is particularly useful for positioning the load at specific angles or for maneuvering loads in tight spaces.

3)Safety Mechanism:

The hook latch ensures that the load is securely held during lifting and lowering operations. By automatically closing the throat of the hook, the latch prevents the load from accidentally detaching during transit, which is a critical safety feature.Safety pins or additional locks can be used to prevent unintentional release of the latch.

Motor

Functions and Roles of the Crane Motor in Different Systems

1)Hoisting System:

The motor in the hoisting system is responsible for providing the mechanical power needed to lift and lower loads. It is connected to a gearbox, which translates the motor's rotational power into vertical movement.

Depending on the crane's load requirements, the motor may be rated for high torque to lift heavy loads or high speed for quick movements.

2)Bridge Traveling System:

The bridge traveling motor drives the end carriages, which allow the entire crane to move horizontally across its span. The motor typically drives a reduction gear that transfers power to the wheels of the crane.

This motor enables the crane to travel along the runway rails, moving the entire structure of the crane from one location to another.

3)Trolley Traveling System:

The trolley motor drives the trolley mechanism, allowing the hook and load to move horizontally along the girder. This motor provides the power needed to move the trolley back and forth.

For larger cranes, the trolley may have a separate motor to ensure smooth and independent movement of the hook across the girder.

.

Sound and light alarm system & limit switch

1. Sound and Light Alarm System

The sound and light alarm system provides both audible and visual signals to alert operators and personnel about the crane's operational status or potential hazards. This system is especially important in busy or noisy environments where the operator may not always be able to see or hear everything around them. The combination of lights and sounds ensures that warnings are more noticeable and effective.

2.Limit Switches

Limit switches are mechanical or electronic devices used in cranes to automatically stop or limit the movement of the crane's components (e.g., the hoist, trolley, and bridge) when they reach a pre-defined limit. These switches are critical safety devices designed to prevent damage to the crane and the load by stopping movement at specific points to avoid over-travel, over-lifting, or collision.

10.Safety Devices

1) Overload Protection Device

The overload protection device is designed to prevent the crane from lifting a load that exceeds its rated capacity, which could cause structural damage or a dangerous failure.

2)Limit Switches

Limit switches are mechanical or electronic devices designed to stop the crane's movements when certain travel limits or positions are reached. These switches prevent the crane from moving beyond its safe operating range.

3)Emergency Stop Button

The emergency stop (E-Stop) button is a crucial safety feature that allows the operator to immediately stop all crane movements in case of an emergency.

4)Safety Interlocks

Safety interlocks are mechanical or electrical devices that prevent the crane from operating under unsafe conditions. They work by preventing the crane from starting or continuing its operation unless all safety parameters are met.

5)Brake Systems

Brake systems are essential for preventing uncontrolled movement, especially during hoisting or traveling.

11.Control Mode

1)Pendant Control (Wired Control)

Pendant control is one of the most common control modes for overhead cranes. It involves using a wired control system that is physically connected to the crane via a cable.

2)Radio Remote Control (Wireless Control)

Radio remote control is a more flexible and modern control method that uses wireless technology to control the crane's movements. This system is becoming increasingly popular because it provides more freedom of movement for the operator.

3)Cabin Control (Operator Cabin Control)

In cabin control mode, the operator controls the crane from a fully enclosed operator's cabin mounted on the crane's bridge or trolley. This mode is typical for cranes that require high precision, long travel distances, or operation in harsh environments.

4)Automatic Control (Automated or Semi-Automated Control)

Automatic control is a high-tech control mode that is used to automate certain functions of the crane. This system is commonly found in smart cranes or those used in environments that require repetitive lifting tasks.

12.Sketch

Main technical

 

 

1. Increased Load Capacity

Higher Capacity: Double girder cranes typically have a higher lifting capacity than single girder cranes due to the added structural support from two parallel girders. This allows them to handle heavier loads, making them suitable for demanding industrial applications.

2. Better Stability and Safety

More Stable Design: The two girders on a double girder crane provide greater structural stability, which reduces the risk of twisting or flexing under heavy loads. This makes the crane safer and more reliable, especially in environments where high precision is required.

3. Higher Lifting Height and Longer Span

Increased Hook Height: Because the double girder design provides more clearance between the bridge and the lifting mechanism, it allows for higher lifting heights compared to single girder cranes.

4. Improved Performance and Speed

Faster Hoisting and Traveling: Double girder cranes can be equipped with more powerful motors and a more robust drive system, allowing for faster hoisting, trolley, and bridge movements. This improves overall efficiency and productivity, especially in environments that demand quick and precise lifting operations.

5. Versatility in Application

Adaptable to Various Industries: Double girder cranes are incredibly versatile and can be customized with various lifting systems, hoists, and other attachments. They can be used in a wide range of industries, including steel mills, automotive manufacturing, ports, and warehouses.

 

 

1. Manufacturing and Assembly Lines

Heavy Equipment Handling: Double girder cranes are used in manufacturing plants for lifting and moving heavy machinery, production components, or assembly line parts.

Assembly Line Operations: These cranes are used to move large, heavy parts along production lines, especially in industries like automotive manufacturing, where precise and efficient handling of car parts is critical.

2. Steel Mills and Foundries

Lifting Molten Metal and Heavy Steel: In steel mills, foundries, and metalworking plants, double girder cranes are often used to lift and transport molten metal (in ladles), steel beams, and metal billets.

3. Shipyards and Port Operations

Container Handling: Double girder cranes, also known as gantry cranes, are commonly used at ports and shipyards for lifting shipping containers, cargo, and ship parts.

4. Warehouses and Distribution Centers

Storage and Inventory Management: Double girder cranes are used in large warehouses and distribution centers to move heavy pallets, raw materials, or finished goods between storage areas and loading docks.

5. Construction Sites

Material Handling: In construction, these cranes are used for lifting and moving building materials such as steel beams, concrete panels, and heavy equipment.

 

 

1.Design and Engineering:

The process begins with designing the crane based on specifications such as load capacity, span, and operating conditions. Engineers create 3D models and detailed technical drawings.

2.Material Procurement:

High-quality steel and other components (motors, hoists, electrical systems) are sourced from certified suppliers.

3.Fabrication of Structural Components:

The main girders, end carriages, and trolley frames are fabricated by cutting, welding, and machining steel. The crane's frame is assembled with precision.

4.Machining and Assembly:

Crane wheels, axles, and hoist mechanisms are machined and assembled. The trolley, hoist, and control systems are integrated into the crane structure.

5.Electrical System Installation:

Electrical wiring, motors, limit switches, and safety devices are installed. The electrical system is tested for functionality.

6.Painting and Surface Treatment:

The crane is cleaned, primed, and painted for corrosion protection and aesthetics.

7.Testing and Quality Control:

Load testing, functionality checks, and safety inspections are conducted to ensure the crane meets performance and safety standards.

8.Packaging and Delivery:

After passing tests, the crane is disassembled (if needed), packed securely, and shipped to the client.

9.Installation and Commissioning:

Upon delivery, the crane is installed, assembled on-site, and tested again for operation before commissioning.

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%.