Underhung bridge crane

▶The underhung bridge crane also known as under running overhead crane or underhung overhead travelling crane, is a versatile and compact crane system commonly used in machinery, assembly sites, warehouses, and other places. It is typically used in conjunction with the CD1 or MD1 electric hoist, offering lifting capacities from 0.5 to 10 tons and spans ranging from 3 to 22.5 meters. The crane operates efficiently under working levels A3-A4 and in environments with temperatures ranging from -25℃ to +40℃, relative humidity ≤85%, and no exposure to flammable, explosive, or corrosive materials.

▶This type of crane has several advantages, including a compact structure, good rigidity, easy operation, low noise, safety, reliability, and a sleek appearance. It is installed by attaching directly to the existing roof structure, eliminating the need for runway support columns, thus maximizing the available floor area for production. In situations where the building lacks a prepared runway beam, underhung cranes can be installed by using the existing ceiling trusses or roof structure. These cranes offer excellent side approach, optimal use of the building’s width and height, and are ideal for buildings with limited vertical clearance.

▶An underhung single girder crane is typically used for lighter service, while a double girder crane can run its hoist along the top or bottom of the bridge beams. For buildings without the necessary support structure, underhung cranes can be designed in a free-standing configuration with mounting columns. Additionally, underhung bridge cranes can be designed with a telescopic structure, extending the crane’s range and allowing for lifting outside of windows, which is beneficial for specific applications.

Underhung bridge cranes are widely used in parts assembly, manufacturing and processing, pallet loading, injection molding, warehousing loading and unloading, and equipment maintenance due to their light lifting capacity.

❏Single Girder Underhung Bridge Crane

Load Capacity: 1-10t

Span: ≤20m

Lifting Height: 6-18m or according to your needs

Voltage: 220-660v 50/60Hz 3Phase

Working Class: A3, A4

Ambient Temperature: -25℃-40℃

❏Double Girder Underhung Bridge Crane

Load Capacity: 1-16t

Span: ≤20m

Lifting Height: 6-18m or according to your needs

Voltage: 220-660v 50/60Hz 3Phase

Working Class: A3, A4

Ambient Temperature: -25℃-40℃

◈Bridge steel structure part: The electric suspension crane bridge frame consists of the main beam and end beam. The main beam is the primary load-bearing component, with its lower flange serving as the running track for the electric hoist.

Electric suspension cranes are designed with cantilevers of 500mm, 750mm, or 1000mm depending on the span. It is crucial that no negative wheel pressure occurs on the opposite side when the hoist is fully loaded at the cantilever end.

The end beam device is located at both ends of the main beam and is connected via a hinged plate. Rubber buffers are installed at both ends to prevent damage from collisions. The crane uses a balance shaft connection between the main beam and end beam for easy installation, transportation, and storage.

◈Electric trolley: It consists of two electric trolleys and two driven trolleys, connected to the end beam by bolts beneath the wall panel.

◈Motor: The motor used is a ZDY series conical rotor brake motor, known for its excellent heat dissipation, long lifespan, and reliability.

◈Driving device: It is made from HT200 gray iron for strong anti-vibration performance, while the gears and gear shafts are forged from 40Cr, with a hardness of HB235～269.

◈Electric hoist: The electric hoist used on the underslung overhead crane undergoes both dynamic and static load tests, as well as rise and drop pressure tests. A baking paint process is applied to improve paint adhesion and appearance quality, ensuring consistency through the assembly line.

◈Control mode: Pendant panel, Remote control. The crane can be equipped with both ground and remote control, but only one mode can be used at a time for safety reasons. The control circuit uses a safe AC 36V voltage.

◈Electrical control system: Ensure the crane’s safe, accurate, and reliable operation, providing excellent transmission, monitoring, and protection capabilities.

Support Structure:

Under running cranes are suspended directly from the roof structure or another overhead beam, eliminating the need for additional support columns. In contrast, top running cranes require independent columns to support the end trucks and bridge beam.

Capacity:

Under running cranes are typically used for lighter loads, with capacities usually below 10 tons. On the other hand, top running cranes can handle much heavier loads, with safe working loads reaching up to 550 tons, making them suitable for large-scale industrial applications.

Configuration:

Due to their lighter capacity, under running cranes often utilize a single girder configuration. However, double girder under running cranes are available for specific applications. Top running cranes, equipped with a double girder design, are more common, offering increased strength and lifting capabilities.

Space Utilization:

A key advantage of under running cranes is their ability to make optimal use of vertical space, even in areas with limited height. They are ideal for tight spaces and low-clearance environments, ensuring efficient material handling where space is at a premium.

Installation and Maintenance:

Under running cranes are easier and quicker to install as they don’t require the construction of support columns. Their compact design also simplifies maintenance. In contrast, top running cranes, with their more complex support structure, can take longer to install and may require more extensive maintenance.