overhead crane definition

An overhead crane is a type of lifting equipment widely used above workshops, warehouses, and material yards, and is mainly used for lifting materials. Its structural feature is that it spans above the working area, with both ends built on concrete columns or steel structure brackets, and its overall shape resembles a bridge, so it is also commonly known as an "bridge crane" or "overhead traveling crane". In this article, we will take you to understand what is an overhead crane? As well as definitions, components, types, applications, costs and more to help you make a better choice of bridge crane solutions.

Overhead Crane

what are the parts of an overhead crane

The components of overhead cranes vary according to their structural design and are mainly categorized into two types: single girder type and double girder type. Whether it is single girder type or double girder type crane, its core components include hook set, wire rope, reel set, reducer, brake and electrical control system. The following are their structural characteristics and description of the main components:

Single Girder Overhead Crane Components

Die Struktur der single girder overhead cranes is relatively simple, mainly consisting of a main girder, end girder, electric hoist and running mechanism. The main girder usually adopts box or I-beam design, and the electric hoist runs along the lower flange of the main girder to complete the lifting and horizontal movement of materials. Its running mechanism includes large and small trolleys, which are responsible for longitudinal and transverse movement respectively. Single girder cranes are suitable for light and medium loads, and are characterized by small footprint and low cost.

Single Girder Overhead Crane Components

Double Girder Overhead Crane Components

Double girder overhead cranes consist of two parallel main girders, end girders, hoisting mechanism and trolley running mechanism. The main girders are connected with each other by cross girders to form a stable frame structure. The hoisting mechanism is usually mounted on the trolley, which runs along the upper flange of the main girder and is capable of carrying larger tonnage loads. Double girder cranes are suitable for heavy material lifting, with the advantages of high stability and strong load carrying capacity.

Double Girder Overhead Crane Components

how does an overhead crane work？

The overhead crane mainly completes lifting operations through the cooperation of electric hoist and trolley. The following is its working principle and operation mechanism:

  1. Drive of electric hoist
    The electric hoist is the core lifting device of overhead bridge crane, which is mainly composed of motor, reducer, drum and wire rope (or chain). The motor converts high-speed rotation into low-speed high-torque output through the reducer, drives the drum to rotate, thereby driving the wire rope or chain to achieve the lifting and lowering of the hook, and can also accurately adjust the height of the hoisted object through the control system.
  2. Horizontal movement of electric trolley
    The electric trolley is a key component for overhead bridge crane to achieve horizontal movement, and is usually installed on the main beam track. The trolley is driven by an independent motor and runs along the track through a gear or belt drive system. The operator can adjust the moving speed and direction of the trolley through the control system to accurately transport the hoisted object to the target location.
  3. Dual support of bridge and track
    The bridge of the overhead crane is usually composed of a single-beam or double-beam structure, and the two ends of the bridge are supported on the track by end beams. The track system adopts a double-track design, which makes the crane stable and balanced when moving longitudinally.

overhead crane types

There are many types of overhead cranes to meet the wide range of needs from basic material handling to special industry applications, which can be carefully divided as follows:

Division of spreader types

  • Hook type crane: adopts standard hook as spreader, widely used in all kinds of material handling scenarios, with strong versatility and easy operation.
  • Grab cranes: specially designed with a grab device, suitable for grabbing bulk materials such as coal, ore, etc., to improve loading and unloading efficiency.
  • Electromagnetic Piston Crane: Utilizing electromagnetic principle to adsorb metal objects, suitable for metal material handling in steel mills, etc., with precise control and non-contact lifting.

Differentiation of application fields

General-purpose overhead cranes

  • Applicable to a variety of operating environments, comprehensive functions, is a common lifting equipment in factories and warehouses.
what is an overhead crane

Specialized overhead travelling crane

Designed for specific industry needs, including but not limited to:

  • Forging overhead travelling crane: designed for forging workshops, capable of withstanding high temperatures and shock loads.
  • Metallurgical bridge cranes: adapted to the harsh environment of the metallurgical industry, with high temperature and wear resistance.
  • Power Station Overhead Cranes: used for power station maintenance, capable of lifting heavy power generation equipment.
  • Explosion-proof overhead travelling crane: suitable for flammable and explosive places to ensure operational safety.
  • Insulated overhead travelling crane: designed for use in electrical work areas to prevent current conduction.
  • Heavy-duty bridge crane: lifting capacity from 50 ton-500ton, designed for heavy cargo lifting, with super lifting capacity.

Main beam structure classification

  • Box type overhead travelling crane: the main girder adopts closed box structure, high strength, good stability, suitable for heavy load operation.
  • Truss bridge crane: the main girder is constructed in the form of truss, which reduces the weight and maintains sufficient strength, and is suitable for occasions with large span.
  • Pipe Structure Overhead Crane: Pipes are arranged inside the main girder for transmission of medium or as structural support, mostly seen in special process requirements.
  • Girder cranes: simple profile girders made of steel sections (e.g. I-beams) and steel plates are used with electric hoists as lifting mechanism, which is economical and practical and suitable for light to medium load operations.

what is an overhead crane used for

  • Automotive and Transportation: Overhead cranes move materials on automotive assembly lines to improve efficiency, and in the transportation industry they mainly assist in unloading ships and speeding up the movement of large items.
  • Aerospace: Bridge cranes are primarily used in the aerospace industry in hangars to move heavy machinery accurately and safely, and are suitable for handling expensive items.
  • Concrete Manufacturing: Efficient and safe movement of ready-mixed and pre-formed parts, often used indoors in factories, while tire gantry cranes are often used in outdoor yards.
  • Metalworking: for handling raw materials, melting drums and loading finished products, attachments can be added to move different metal products.
  • Power plant: mainly used in thermal, hydro, wind power plant indoor material handling operations.

what is the cost of an overhead crane?

We have provided price ranges for overhead cranes of different tonnages in the table below. These prices are for reference only, and the exact price of the overhead bridge crane will depend on your detailed customization needs at the time of actual purchase.

Tragfähigkeit Spannweite Price Range
10-20 ton10-20m$39,000 - 78,000
20-50 ton10-30m$78,000 - 198,000
50-100 ton10-30m$198,000 - 480,000
100-500 ton10-30m$480,000 - $1,200,000+

Key factors that will affect the price

  • Span and Lifting Height: In addition to tonnage, the span and lifting height of the crane are important factors in determining price. Wider spans and higher lifting heights often require more complex structures and stronger materials, which increase manufacturing costs.
  • Working environment and special requirements: If the bridge crane needs to work in extreme or special environments (e.g., high temperature, low temperature, humidity, corrosive environments, etc.), it may need to be made of special materials and coatings to meet the requirements of anti-corrosion, anti-explosion, anti-magnetic and so on.
  • Configuration and additional features: different configurations and additional features will also significantly affect the price. For example, bridge cranes with remote control operation, variable frequency speed control, energy recovery and other features, as well as equipped with advanced safety devices, are usually more expensive.
  • Degree of customization: If you need a highly customized bridge crane, such as special track layouts, non-standard sizes or special-purpose spreaders, these will require additional design and manufacturing costs, so the price will be higher accordingly.

To ensure that you get the bridge crane solution that best meets your needs, please feel free to contact us and we will provide you with an optimized customized solution based on your specific working condition requirements and budget.

overhead crane Use and maintenance precautions

Use and maintenance precautions for key components of overhead cranes:

  • Hook group: it is the device that carries materials directly, the surface of the hook must be kept smooth, and cracks or other damages are strictly forbidden to ensure the safety of lifting operation.
  • Pulley group: including dynamic pulley group and fixed pulley group, the surface of which must not have cracks, and the pulley must be ensured to rotate flexibly when working. If the pulley is damaged, it is forbidden to repair it by welding and should be replaced in time.
  • Steel wire rope: It should be inspected regularly to ensure that there are no broken wires, broken strands, knots, rust or pockmarks.
  • Reel group: it is the core component of winding wire rope in the hoisting mechanism, and its surface should be ensured to be smooth, so as to avoid wear and tear or jumping groove of the wire rope in the process of operation.
  • Reducer: It is used to reduce the high speed of the motor to the required speed. It should be run smoothly without jumping, impact or abnormal noise, while checking whether the fasteners are loose.
  • Coupling: Used to connect two coaxial or parallel shafts to transmit torque and compensate for angular and radial offset. Their connection status should be checked periodically to ensure that there is no looseness or wear.
  • Brakes: Usually installed on high-speed shafts to reduce braking torque. It is necessary to ensure that the brake pads have no burn marks or odor, and that the friction surface of the brake wheel is not contaminated with oil.
  • Wheel group: assembled by wheels and angle steel bearing box. When the wheel rim is worn less than 10mm, it needs to be reported and closely observed, and replaced if necessary.
  • Buffer: used to absorb the energy generated when the crane or trolley collides with the baffle, its elasticity performance needs to be checked regularly to ensure its buffering effect.
  • Resistor: as an electrical appliance to limit the current of the motor, it is necessary to ensure that its working condition is normal to avoid overheating or damage.

For more details or to get a quote, please contact our service team.