Dongqi Crane provides customized overhead crane systems to customers from all walks of life. For our engineers, in order to ensure that the overhead crane can serve customers perfectly, it is necessary to have an in-depth understanding of the specific environment in which the overhead crane is required to be used. and work tasks such as span, load, working environment (indoor/outdoor, high/low temperature, wet/dry, etc.). It is also necessary to analyze the frequency of use of the crane, its working cycle and the special challenges it may face, such as accuracy requirements, speed requirements, etc.

Although we have a complete workflow, it is also enlightening for us to understand the design options of overhead cranes in uncharted territory. The important case shared by Dongqi today is the supply of 2 bridge cranes to an aircraft wing manufacturing factory. We will gain knowledge about overhead cranes for interested customers by analyzing their design process and work content.

What work does a bridge crane do in an aircraft wing manufacturing factory?

The crane will produce composite wings and components for commercial aircraft and business jets to fulfill an order for 138 passenger aircraft.

They have four suspension points and a pin joint system for curved crane beams and removable roofs.

The spans between the crane tracks of the two bridge cranes are 20m and 25 m respectively. The tracks are integrated into the roof structure and feature cantilevered extensions, giving the system greater coverage.

Crane companies say that when installing the crane beam, they took care to reduce the overall depth of the crane and provide maximum working height. The crossbeam is suspended from under the traveling track, while the hoist is suspended from under the crane bridge.

The crane company offers electric hoists that provide a 6m lift height for all cranes.

The crane company said it equipped the main production area with a four-axle 20-ton single-girder crane, which has a completely different design than those commonly seen on the market.

The crane company explains that the 20-ton ‘jiggle’ crane is used with 15-ton and 10-ton cranes for precise positioning.

“On a jiggle crane, the first hoist carries most of the weight of the wing and the second hoist provides lateral adjustment, allowing the wing to rotate 600mm and an additional plus or minus 300mm about the beam axis,” it said.

“This multi-span crane has four suspension points with a total span of 64m and a jib at each end. The box girder design provides the required strength and stiffness, with pinned connections providing the crane girder with flexibility of movement, So that it can flex as the roof moves.”

In the assembly area, an 8-ton underslung twin-girder crane rotates the wing half a turn (200 degrees) on twin swivel hoists.

“The lifting and walking motion, with walking speeds ranging from 400 mm per minute to 20 m per minute, uses sensorless current vector control for precise positioning and smooth movement,” the company said. A radio remote control is included with the order to provide Safety and ease of use, and comes with a push button pendant as a backup control. “

Includes load capacity limiter, audible alarm and flashing amber warning light for added safety.

The aircraft manufacturer’s system ensures the wings can move along a 52m pinned crane bridge. The turntable is equivalent to a 5m long small crane running on a circular track between the main crane girders.

What skills do you need to master when designing a bridge crane?

Understand application areas and job requirements:

• Have an in-depth understanding of the specific environment and operating tasks required for overhead crane applications, such as span, load, and working environment (indoor/outdoor, high/low temperature, wet/dry, etc.).
• Analyze the crane’s usage frequency, working cycle, and possible special challenges, such as accuracy requirements, speed requirements, etc.

Master the basic structure and working principles:

• The basic structure of the bridge crane includes the bridge frame, the trolley operating mechanism, the trolley operating mechanism, the lifting mechanism, etc.
• Understand the working principles and interactions of key components such as motors, reducers, couplings, drums, wire ropes, pulleys, and brakes.

Identify key parameters and performance indicators:

• Carrying capacity: According to the actual operating requirements of the application field, the crane’s carrying capacity is reasonably designed.
• Stability: Consider the crane’s center of gravity, chassis width, shock absorption measures, etc. to ensure stability during operation.
• Operating speed: Design a reasonable operating speed based on actual operating efficiency and safety requirements.
• Maneuverability: Design a control system that is easy to operate and maintain. For large cranes, consider using a remote control operating system.

Material selection and structural design:

• Select appropriate materials, such as steel type and strength grade, according to the environment and operating requirements of the application field.
• Conduct structural design and analysis to ensure that the crane achieves lightweight design while meeting strength and stiffness requirements.

Security and reliability considerations:

• Design multiple safety protection measures, such as overload protection, limit protection, anti-overturn protection, etc.
• Considering the durability and reliability of the crane, high-quality components and advanced manufacturing processes are used.

Comply with standards and regulations:

• Ensure that the design complies with relevant standards and regulations for crane design, manufacturing, installation and inspection in your region or country.

Use advanced simulation and analysis tools:

• Use tools such as finite element analysis (FEA) to analyze the strength, stiffness and stability of the crane structure.
• Simulate the operation process of the crane through dynamic simulation and optimize the design plan.

Consider ease of maintenance and repair:

• Design structures and components that are easy to inspect and repair so that repairs can be made quickly if a failure occurs.
• Detailed maintenance and repair manuals are provided to help users perform routine maintenance and care correctly.

Work with domain experts:

• If you are not familiar with the application field, it is recommended to cooperate with experts or consultants in the field to jointly develop a design plan.

To sum up, the design of bridge crane requires the comprehensive use of multi-disciplinary knowledge such as mechanical engineering, materials science, control engineering, etc., and at the same time, customized design based on the characteristics and requirements of the application field. Through continuous learning and practice, and gradually mastering these skills, you will be able to design an efficient, safe, and reliable overhead crane that meets actual needs.