Trelleborg Sealing Solutions’ Orkot® TXMM bearing material has proven to be one of the best in direct electric motor propulsion systems on ships. The motors operate at low shaft velocities and, subject to boundary lubrication, bearings used must demonstrate exceptional wear resistance.
An extensive test program was conducted to prove Orkot® TXMM bearing material performance at low velocities. Bearings were tested to extremes: velocities down to 5 meters/16 feet per minute at pressures up to 6 bar/87 psi and water flows down to 2 liters/4 pints per minute. The seawater contained Silica flour at 250 parts per million, and the 200 mm/8-inch bearing operated on an LG4 Bronze sleeve for 2,000 hours. The resulting overall wear of the bearing was just 0.027 mm/0.001 inch per 1,000 hours, and shaft wear was minimal with an improved shaft finish. The tests were repeated successfully with Inconel and Nickel Chrome Boron coated shafts.
“Orkot® is a unique material. Resistant to seawater, it is proven in numerous marine applications,” says Marty Hugney, marine segment manager for Trelleborg Sealing Solutions Americas. “The bearings perform exceptionally in demanding low velocity situations. This translates into benefits for our customers. Orkot® bearings have almost twice the bearing life of alternative products.”
Orkot® Marine Bearings are manufactured from unique synthetic composite incorporating solid lubricants. Virtually no swelling in seawater and very low thermal coefficient of expansion provide dimensional stability in arctic and tropical seas. The bearings do not corrode or promote corrosion of the housing and tolerate both edge loading and misalignment.