Thornhill, ON – Federal-Mogul has developed maintenance-free bearings for one of the world’s longest suspension bridges. Upon completion, the Hardanger Fjord Bridge in southwest Norway will be one of the largest in the world, spanning 1,310 m (4,297 ft) between pylons.
A total of 128 spherical plain bearings using the company’s deva.bm self-lubricating material technology will accommodate the small but essential movements that occur between the bridge and its supporting cables. The thin-walled, self-lubricating sliding material addresses this issue by providing a large load-carrying surface, providing sufficient durability for the life of the bridge without repair or replacement.
The complete bridge includes 120 spherical plain bearings with a shaft diameter of 160 mm and eight with a shaft diameter of 300 mm, used for the main retaining cables adjacent to the two bridge towers.
The joint balls are made from stainless steel, which is pressed into a plain bearing made from deva.bm. A low-friction sliding bearing consists of a backing comprising steel, stainless steel or bronze, with a deva.metal surface layer. This surface layer is a bronze material manufactured using powder metallurgy – it is not porous and oil-impregnated, but rather highly compressed and coated with a layer of solid lubricant material, such as graphite or PTFE.
The bearing housing forms a two-part spherical ring, also lined with deva.bm, to provide an extended, maintenance-free service life, high static and dynamic load capacity, and low friction properties resulting from layers of homogeneous solid lubricants. The design is completed using thrust washers that are also made from deva.metal, which absorb axial forces.
The bearings are designed for dry running at slow sliding speeds with very high resistance and are well-suited for extreme temperatures and corrosion.