Gantry Crane Structure

The bridge, also known as the girder, is the primary horizontal beam that spans the width of the crane. It is responsible for supporting the hoist and the load it carries. Gantry cranes can have a single girder or a double girder, depending on the lifting requirements. Single girder gantry cranes are typically used for lighter loads, while double girder gantry cranes are designed for heavier capacities and longer spans.

• The material of the main beam is Q235-B, and the minimum plate thickness is not less than 6mm. The main beam can extend out of the legs to one or both sides to form a cantilever, thus increasing the operation range of the crane. The length of the cantilever is generally less than or equal to 1/3 of the span length.
• The end beam is a box-shaped structure, and the connection between the end beam and the main beam is a rigid connection. In order to facilitate transportation, the main beam and end beam are connected by high-strength bolts, and each connecting plate is positioned by reamed bolts.

The legs are vertical structures that support the bridge and connect it to the ground or to rails. These legs are crucial for maintaining the stability and balance of the lifting equipment.

The leg adopts a trapezoidal cross-section structure with a large upper and a small lower section. The upper flange of the leg and the main beam flange support are connected by high-strength bolts, and the lower flange of the leg and the upper connecting flange of the lower cross beam are connected by high-strength bolts.

The hoist is the lifting mechanism of the gantry crane. It comprises a motor, a drum or chain, and a hook or lifting attachment. The hoist moves along the length of the bridge, lifting and lowering loads with precision. The hoisting mechanism adopts a series resistance speed control system with stable braking, small impact and accurate hook positioning, which not only improves the production efficiency, but also greatly extends the service life of the parts of the hoisting mechanism.

The trolley is a mechanism that carries the hoist along the bridge. It moves horizontally, allowing the crane to position the load accurately.

Gantry cranes can be equipped with different lifting attachments to handle a variety of loads, including:

• Hook lifting attachments for almost any type of gantry crane.
• Beam lifting clamps, concrete beam spreaders, adjustable beam sling and hook systems, or other lifting attachments for concrete beam gantry crane.
• Grab buckets for grab gantry crane.
• Electromagnetic or permanent magnets for electromagnetic gantry crane.

The crane running mechanism is a critical structure of gantry cranes, responsible for facilitating their movement along a predetermined path. This mechanism typically includes a set of wheels or rollers, driven by electric motors, that enable the crane to traverse along rails or tracks. It consists of a motor, transmission system, and wheels that ensure smooth and stable motion. The wheels can be rubber-tyred for mobility in rubber tyred cranes or steel wheels for rail-mounted gantry cranes. Additionally, the running mechanism incorporates braking systems for safety and control, allowing precise positioning of the crane during operations. This integrated system ensures the crane can efficiently and accurately move heavy loads within its operational area.

The runway is a set of tracks on which the crane travels. These rails can be mounted on the ground or elevated on a structure, depending on the operational requirements. The runway ensures smooth and precise movement of the crane along the designated path.

The control system is the interface through which the operator controls the crane’s movements. It can be a simple pendant control or a sophisticated radio remote control and cabin control, offering various levels of functionality and safety features. The control systems often include advanced features such as anti-sway technology, load monitoring, and automated positioning.

Gantry cranes primarily operate using direct electrical power supplied through systems such as cable reels or festoon systems. In a cable reel system, a cable winds and unwinds as the crane moves, maintaining a constant connection to the power source. Alternatively, festoon systems use trolleys that support and guide the power cables along a track, ensuring smooth and uninterrupted power delivery. These methods provide reliable and efficient power to the crane’s motors, controls, and lifting mechanisms, enabling precise and robust operation in various industrial environments.