'Pioneering’ order
Published: 27 August, 2015
Schaeffler told ODEE it has been able to obtain its largest order for ELGES spherical plain bearings to date for the “Pioneering Spirit” (formerly "Pieter Schelte") working ship. Schaeffler is supplying a total of more than 240 bearings with outside diameters ranging from 400 to 1060 mm for the "topsides lift system", which is used for oil platform installations. ODEE reports.
Plain bearings can fully demonstrate their advantages in crane and water power applications, as they are perfectly suited to the slow rotary, swivelling, and tilting motions that occur there under very high loads. Schaeffler has systematically expanded its range of plain bearing solutions and offers a wide range of maintenance-free plain bearing materials. In addition to the maintenance-free plain bearings with ELGOGLIDE that the company says have proven themselves for many years, the product range also includes metal-polymer composite plain bearings and plain bearings with ELGOTEX.
With a length of 382 metres and a width of 124 metres, The Pioneering Spirit, designed and built by the Dutch-Swiss offshore company Allseas, is the world’s largest ship. In addition to installing oil platforms and laying pipelines, it is equipped with a "topsides lift system" (TLS) that has a capacity of up to 48,000 tons and enables the installation of even the heaviest platform topsides, while its "jacket lift system" (JLS) can remove and install steel platform substructures weighing up to 25,000 tons in one piece.
Schaeffler explained to ODEE that it supplies maintenance-free large spherical plain bearings with an ELGOGLIDE sliding layer to Allseas for the TLS levers and to Bosch Rexroth for the TLS hydraulic cylinders.
As soon as the ship moves around a drilling platform that is firmly anchored to the seabed, the enormous loads caused by the waves and acting on the ship have to be compensated. The TLS levers allow for these wave motions. The hydraulic cylinders of the TLS in turn ensure that the platform topsides can be elevated and lifted off safely without any damage occurring. The bearings must have a very high load carrying capacity, both for load compensation and to allow for the motion of the hydraulic cylinders.
Its spherical plain bearings in X-life quality are equipped with robust and maintenance-free ELGOGLIDE material. Offshore use of the bearings requires very high corrosion resistance, high moisture resistance for the sliding material, and freedom from maintenance over an operating life of at least 25 years. The bearings have been certified by Lloyd's Register to meet the safety requirements of the marine industry.
The screw connection of the axially split outer ring was optimised as part of the introduction of X-life for ELGES large spherical plain bearings. The fabric additionally undergoes special treatment before the hardening process in order to improve its adhesive properties and optimise moisture resistance. Overall, X-life optimisation has resulted in 15% higher load ratings and a 15% increase in rating and operating life. This also means additional benefits for the customer, including downsizing opportunities and a higher power density, longer service intervals, and an increase in overall cost-effectiveness (TCO).
ELGOGLIDE
The advantages of bearings with ELGOGLIDE are their total freedom from maintenance and very high load carrying capacity, especially in the case of very high unilateral loads and swiveling motion. ELGOGLIDE stands for a sliding layer that primarily comprises a technical woven material made from support fibers, PTFE fibres, and a synthetic resin matrix. Its special ELGOGLIDE W11 variant allows minimal friction values even at low pressures.
Metal-polymer composite plain bearings
The special characteristics of metal-polymer composite plain bearings are down to the combination of plastic and metal materials. This material compound enables low-wear sliding characteristics combined with a high load carrying capacity and thermal conductivity.
The resistance of the metal-polymer composite plain bearings has been tested for a wide range of media. The optional design with bronze backing allows the bearings to be used in water. The metal-polymer composite plain bearings are a cost-effective alternative for applications with minimum available space and a comparatively high sliding speed.
ELGOTEX
Bearing positions subjected to high loads, are conventionally equipped with solid plain bearings lubricated with grease or oil. Plain bearings with ELGOTEX are an ideal replacement for existing solutions requiring maintenance that uses environmentally friendly and maintenance-free technology. These bearings are maintenance-free throughout their operating life due to the material combination used, and are perfectly suited to use in tough environmental conditions.
INA plain bearings with ELGOTEX WA were specially developed for use as rudder bearings and in stabilisers for marine applications. Germanischer Lloyd has certified ELGOTEX WA for loads of up to 15 N/mm² in marine applications. The salt water-resistant ELGOTEX WA material comprises two layers. The internal sliding layer, which is embedded in a resin matrix with fillers and solid lubricants, is made of continuous synthetic and PTFE fibers. The external layer also comprises continuous glass fibres in epoxy resin. This combination of materials allows a consistently low friction value and a low level of wear to be achieved in addition to absolute freedom from maintenance.
