A gantry crane is a typical rail-mounted crane with a slewing boom, also known as a gantry crane! A gantry base is established along the ground track, allowing railway trains and other vehicles to pass under it. This setup is designed for loading, unloading, and transshipment operations involving vehicles and ships. Gantry cranes are commonly found in ports, docks, mines, power stations, and other locations for loading, unloading, lifting, and other tasks. They are characterized by a high lifting capacity, a wide working radius, and a broad operational range, enabling them to handle various cargo loading and unloading activities efficiently.
main structure
1. Gantry structure: The crane's supporting part consists of two gantry legs and a crossbeam connected to the top of the gantry legs to form a gantry frame. The gantry legs usually adopt a box or a truss structure, which is highly strong and stable. A trolley running mechanism is installed under the gantry, which enables the crane to move along the ground track to expand the operating range.
2. Rotating platform: Located on the upper part of the gantry, it is the core working platform of the crane. The platform has a lifting mechanism, luffing mechanism, slewing mechanism, driver's cab, etc. The rotating platform is connected to the gantry through a slewing bearing and can rotate 360° around the vertical axis, allowing the crane to operate in different directions.
3. Boom system: connected to the rotating platform, generally composed of a main boom and a jib. The boom can be a truss or box structure with high strength and rigidity. The length and shape of the boom are designed according to different operating requirements. The pitch angle of the boom is changed through the luffing mechanism to achieve horizontal movement of the cargo.
4. Lifting mechanism: This is used to lift and lower cargo. It is mainly composed of a motor, reducer, drum, wire rope, and hook. The motor drives the drum to rotate through the reducer so the wire rope is wound or released, thereby driving the hook to rise or fall. The lifting mechanism is usually also equipped with safety devices such as brakes and limiters to ensure the safety of the lifting operation.
5. Luffing mechanism: This mechanism changes the pitch angle of the boom, thereby changing the horizontal position of the hook. Standard luffing mechanisms include wire rope pulley and hydraulic cylinder types. The wire rope pulley-type luffing mechanism drives the wire rope through the motor to make the boom rotate around the hinge point; the hydraulic cylinder-type luffing mechanism uses the extension and contraction of the hydraulic cylinder to drive the boom to change its luffing, which has the advantages of compact structure and smooth movement.
6. Slewing mechanism: It comprises a motor, a reducer, a slewing bearing, etc., and drives the rotating platform to rotate around the vertical axis. The slewing mechanism enables the crane to operate flexibly within a 360° range to meet the lifting needs of goods in different locations.
7. Trolley running mechanism: It is installed at the bottom of the portal leg and consists of a motor, a reducer, wheels, etc. The trolley running mechanism drives the portal crane along the ground track. Its running speed is usually adjusted according to the operation requirements to move the crane rapidly between different operation areas.
8. Electrical control system: This system controls the operation of various crane mechanisms, including the motor's start, stop, and speed regulation and the interlocking protection between multiple mechanisms. The electrical control system usually adopts advanced PLC (programmable logic controller) technology, which has a high degree of automation, convenient operation, safety, and reliability.
9. Safety protection devices: To ensure the safe operation of the crane, the portal crane is equipped with various safety devices, including a weight limiter, height limiter, amplitude limiter, slewing limiter, trolley travel limiter, windproof device, and buffer. These safety features can promptly issue an alarm and implement necessary protective measures in the event of an abnormal situation, helping to prevent accidents.
