Fish processing at sea with polymer plain bearings Freshly caught fish is often processed directly on board the fishing trawlers. Heading and gutting machines process the fish while all components are exposed to an aggressive mixture of seawater and blood. Baltic Sea cod, Atlantic cod, sea salmon, and haddock fish are processed in two work shifts below deck by machines that weigh up to 1.5 tons. This work is done in rough seas, with multidirectional accelerations, up to three times the gravitational acceleration, acting directly on the machines and their components. State-of-the-art heading and gutting machines made by Baader, in Lübeck, Germany, process up to 32 fish a minute (max. length: 90cm and max. weight: 7kg). The machine components, chains and bearings are exposed to an aggressive mixture of seawater and blood. Maintenance- and lubrication-free polymer bearings are installed in rustproof roller chains that are used to drive main and secondary units. Since the daily operations at sea and the limited number of personnel do not permit any maintenance work on the chain drives, the machine manufacturer Baader relies on the rustproof roller chains ‘12 B-2’ made by Wippermann Engineering, in Hagen, Germany. According to Baader, the previously used conventional roller chains were already worn out after 400 to 450 hours and had to be replaced. However, using the solution with the Marathon Chains from Wippermann, it has now become possible to increase the operating time to 3,000 hours of operation without having to relubricate or retighten the chains. Corrosion is also not a problem since austenitic, rustproof high-grade steels are used. The roller chain’s special joint design means an enormous increase in service life, without maintenance. A high-performance polymer plain bearing from igus was integrated, "which significantly improved the tribological properties of the chain joint," explains Dr. Gunnar Gödecke at Wippermann Engineering. This plastic plain bearing features "extremely high wear resistance, low friction, high pressure resistance, and chemical resistance." Furthermore, Dr. Gödecke explains that this plastic plain bearing is maintenance-free and insensitive to dirt. The design and the selection of materials for the polymer plain bearing used by Wippermann were developed in cooperation with the bearing specialist igus; who was responsible for the selection of materials and for the bearing design. In-house tests conducted at Wippermann then confirmed this selection of materials before series production began. In the past, this cooperation had already led to various tailor-made bearing solutions for the Wippermann chains. Nevertheless, every chain application has other requirements for the components involved. Speed Link InfoService Request more information by e-mail Reader Service No. Reader Number Email Address 01246    Tell a friend about this article:
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