Corrosion-resistant plain bearings in the wave energy converter

Profile

• What was needed: Plain bearing made of the material iglidur Z
• Requirements: freedom from maintenance, corrosion resistance, durability, robustness
• Industry: energy generation
• Success for the customer: the wear-resistant material iglidur Z is designed for high loads under continuous operation. As the bearings are not lubricated externally, no lubricants end up in the marine environment.

The ocean wave energy converter is constantly exposed to sea water and strong waves, which means that the plain bearings in use should also be corrosion-resistant and maintenance-free.

Description of the problem

Among other things, the Spanish company Rotary Wave is dedicated to sustainable energy production using waves and water currents in the sea. One of the business's innovative solutions is the ocean wave energy converter. As the name suggests, the mechanical forces in the seas are converted into electrical energy. The energy converter in the form of a platform floats continuously in the sea, which results in special challenges for the technical components. Here, the focus is on a plain bearing that is used specifically in the roller axis component, which carries the entire load of the piston-cam assembly. This is a central system for converting mechanical energy into hydraulic power. The surface pressures achieved here are around 50MPa and the maximum speed amounts to 10rpm. The plain bearing would be temporarily immersed in sea water without protection. The company initially considered using high-resistance sintered bearings at low speeds.

Solution

In addition to sintered bearings with different surface materials, such as bronze, Rotary Wave also requested our iglidur Z plain bearings so as to carry out comparison tests. The aim was to find a maintenance-free and corrosion-resistant solution for underwater use. With our online tools, the customer was able to quickly access all the necessary technical information regarding the bearings and materials, so that they could determine the best possible solution. After a direct comparison with sintered bearings and a special focus on the wear behaviour in marine environments, Rotary Wave finally opted for the plain bearings made of iglidur Z. The wear-resistant material had been specially designed for high loads in continuous operation. Also important when used in the sea: due to their self-lubricating specifications, the iglidur plain bearings don't require external lubrication. This means that no lubricants can end up in the marine environment.