Hydraulic A-Frame with maximum freedom of movement

Profile

What was needed:
plain bearings for the pivoting kinematics of an A-frame

Requirements: 
self-lubricating and maintenance-free plain bearings that are weather-resistant and suitable for heavy loads

Industry: 
offshore industry

Success for the customer: 
maintenance-free and corrosion-free bearing points, cost-effective, custom-made plain bearings

 

Radius of movement of 180°

For years, Ship & Yacht Engineering Ltd. has specialised in the management and implementation of complex projects in shipbuilding and marine technology. Its founder and CEO, Erik Hofmann, develops everything needed in shipbuilding, from ramps to cruise ships. In his work with various shipping companies, he repeatedly became aware of the disadvantages of A-frames.

He then developed an A-frame with maintenance-free, lubrication-free pivot kinematics for a 180° motion radius, the Linkage System. To minimise maintenance and keep the kinematics bearing points lubrication-free, Hofmann uses iglidur® plain bearings.

Hofmann's novel A-frame stands in the port of Leer in East Frisia, and doesn't seem unlike all others at first. However, closer examination reveals one crucial difference: unlike other hydraulically operated A-frames, this one has no external cylinders. This is the great advantage of Hofmann's innovation. The lifting system is tilted with the linkage system. The cylinders and the special pivot kinematics are installed in the A-frame's frame, allowing a motion radius of 180°.
 

Suitable for up to 20 tons of pivot load

The A-frame of the Ship & Yacht Engineering Ltd. has already been approved by the classification society and can lift loads of up to 20 tons, depending on pivoting angle. Now it is being installed on a research vessel from Fugro, the world's leading geodata specialist, where it will be used, e. g., to drop the magnetometer into the water and lift it out again.

To ensure that the pivot kinematics operates without problems on the high seas and under harsh weather conditions, Hofmann was looking for self-lubricating, maintenance-free plain bearings that were also cost-effective. He had previously used bronze bushings. As weather conditions constantly flushed grease out of the bearings, new grease had to be constantly pumped in to ensure sufficient lubrication and prevent corrosion, the naval architect reports.   

Self-lubricating effect prevents lack of lubrication

A recommendation made Hofmann aware of igus® GmbH, the Cologne-based developer and manufacturer of lubrication-free high-performance plastics. Its plain bearings made of the igutex TX1 material are now used in the A-frame's pivot kinematics. They were developed specifically for high-load applications, minimise maintenance, and require no additional lubrication.

"Our plain bearings contain incorporated solid lubricant, contained in millions chambers in the material, always providing sufficient lubricant for the bearing point. This makes insufficient lubrication impossible," says Uwe Sund, Product Manager for iglidur® heavy-duty bearings. Since no additional lubricant is required, there is no need of manual lubrication or an automatic lubrication system.